Règle correspondante
Canada
Practice Relating to Rule 100. Fair Trial Guarantees
Section G. Examination of witnesses
Canada’s LOAC Manual (1999) provides that accused persons in occupied territory must “have the right to present evidence necessary to their defence and may, in particular, call witnesses”. 
Canada, The Law of Armed Conflict at the Operational and Tactical Level, Office of the Judge Advocate General, 1999, p. 12-7, § 57.
Canada’s LOAC Manual (2001) states in its chapter on rights and duties of occupying powers: “Accused persons have the right to present evidence necessary to their defence and may, in particular, call witnesses.” 
Canada, The Law of Armed Conflict at the Operational and Tactical Levels, Office of the Judge Advocate General, 13 August 2001, § 1232.3.
In 2004, in R. v. Lyttle, the Supreme Court of Canada noted with regard to the right to cross-examine witnesses:
1. Cross-examination may often be futile and sometimes prove fatal, but it remains nonetheless a faithful friend in the pursuit of justice and an indispensable ally in the search for truth. At times, there will be no other way to expose falsehood, to rectify error, to correct distortion or to elicit vital information that would otherwise remain forever concealed.
2. That is why the right of an accused to cross-examine witnesses for the prosecution – without significant and unwarranted constraint – is an essential component of the right to make full answer and defence.
41. As mentioned at the outset, the right of an accused to cross-examine prosecution witnesses without significant and unwarranted constraint is an essential component of the right to make a full answer and defence. See R. v. Seaboyer, [1991] 2 S.C.R. 577, at p. 608, per McLachlin J. (as she then was):
The right of the innocent not to be convicted is dependent on the right to present full answer and defence. This, in turn, depends on being able to call the evidence necessary to establish a defence and to challenge the evidence called by the prosecution. … In short, the denial of the right to call and challenge evidence is tantamount to the denial of the right to rely on a defence to which the law says one is entitled. [Emphasis added.]
42. In R. v. Osolin, [1993] 4 S.C.R. 595, Cory J. reviewed the relevant authorities and, at p. 663, explained why cross-examination plays such an important role in the adversarial process, particularly, though of course not exclusively, in the context of a criminal trial:
There can be no question of the importance of cross-examination. It is of essential importance in determining whether a witness is credible. Even with the most honest witness cross-examination can provide the means to explore the frailties of the testimony. For example, it can demonstrate a witness’s weakness of sight or hearing. It can establish that the existing weather conditions may have limited the ability of a witness to observe, or that medication taken by the witness would have distorted vision or hearing. Its importance cannot be denied. It is the ultimate means of demonstrating truth and of testing veracity. Cross-examination must be permitted so that an accused can make full answer and defence. The opportunity to cross-examine witnesses is fundamental to providing a fair trial to an accused. This is an old and well-established principle that is closely linked to the presumption of innocence. See R. v. Anderson (1938), 70 C.C.C. 275 (Man. C.A.); R. v. Rewniak (1949), 93 C.C.C. 142 (Man. C.A.); Abel v. The Queen (1955), 115 C.C.C. 119 (Que. Q.B.); R. v. Lindlau (1978), 40 C.C.C. (2d) 47 (Ont. C.A.).
43. Commensurate with its importance, the right to cross-examine is now recognized as being protected by ss. 7 and 11(d) of the Canadian Charter of Rights and Freedoms. See Osolin, supra, at p. 665.
44. The right of cross-examination must therefore be jealously protected and broadly construed. But it must not be abused. Counsel are bound by the rules of relevancy and barred from resorting to harassment, misrepresentation, repetitiousness or, more generally, from putting questions whose prejudicial effect outweighs their probative value. See R. v. Meddoui, [1991] 3 S.C.R. 320; R. v. Logiacco (1984), 11 C.C.C. (3d) 374 (Ont. C.A.); R. v. McLaughlin (1974), 15 C.C.C. (2d) 562 (Ont. C.A.); Osolin, supra.
45. Just as the right of cross-examination itself is not absolute, so too are its limitations. Trial judges enjoy, in this as in other aspects of the conduct of a trial, a broad discretion to ensure fairness and to see that justice is done – and seen to be done. In the exercise of that discretion, they may sometimes think it right to relax the rules of relevancy somewhat, or to tolerate a degree of repetition that would in other circumstances be unacceptable. See United Nurses of Alberta v. Alberta (Attorney General), [1992] 1 S.C.R. 901, at p. 925. 
Canada, Supreme Court, R. v. Lyttle, Judgment, 12 February 2004, §§ 1–2 and 41–45.
[emphasis in original]
In 2008, in the Ribic case, Canada’s Court of Appeal for Ontario dismissed an appeal of a Canadian national who had been convicted of hostage-taking. Justice Cronk, who gave the leading judgment, summarized the facts of the case as follows:
[1] In 1995, Bosnia was in the throes of a bitter and prolonged civil war between Bosnian Serbs and Bosnian Muslims. The war had a complicated and violent history. Throughout, a United Nations (UN) peacekeeping force, assisted by the North Atlantic Treaty Organization (NATO), was deployed in Bosnia.
[2] The appellant, Nicholas Nikola Ribic, is a Canadian citizen of Yugoslavian origin. At some point around 1995, he travelled to Bosnia and became involved with the Serbian war effort. On May 26, 1995, Ribic and several companions took three unarmed UN military observers hostage at gunpoint in the Bosnian town of Pale and used them as human shields by shackling them to Serbian ammunition bunkers that were the target of an ongoing NATO air strike. During the initial hostage-taking, Ribic repeatedly threatened to kill the hostages if the NATO bombing did not stop. The hostages were detained for almost three and a half weeks, until their negotiated release on June 18, 1995. …
[3] On February 17, 1999, Ribic was charged with four counts of hostage-taking in relation to two of the UN observers – one of whom is a Canadian citizen – under s. 279.1 of the Criminal Code of Canada, R.S.C. 1985, c. C-46 (the Code). … Canada’s jurisdiction over the hostage-taking, assumed under s. 7(3.1) of the Code, was conceded by the defence.
[4] Ribic’s first trial began in October 2002. It ended on January 20, 2003 with the declaration of a mistrial. On June 12, 2005, following a second trial before a judge and jury, Ribic was convicted of two counts of hostage-taking and, on September 14, 2005, was sentenced to three years imprisonment.
[5] Ribic appeals his convictions. He argues that the trial judge erred by ruling that some of the substantive defences advanced by the appellant should not have been put to the jury and that he further erred in his instructions on certain of the defences left with the jury for its consideration. Ribic also contends that the trial judge erred by refusing to stay the prosecution on the grounds that Ribic’s rights under ss. 7 and 11(b) of the Charter of Rights and Freedoms [(Charter)] to a fair trial [and] to make full answer and defence to the Crown’s case … had been infringed. For the reasons that follow, I would dismiss the appeal. 
Canada, Court of Appeal for Ontario, Ribic case, Judgment, 24 November 2008, §§ 1–5, per Cronk J.A.
The Court held:
[23] The appellant’s first trial began on October 7, 2002 before Cunningham J. of the Superior Court of Justice. The Crown called six witnesses over eight days. On October 23, 2002, at the close of the Crown’s case, the defence sought to call as witnesses two former members of the Canadian Armed Forces who had served in Bosnia with UNPROFOR [UN Protection Force] during the hostage-taking incident. The first proposed witness – Witness A – was a Canadian intelligence officer who acted as Canada’s country analyst for Bosnia- Herzegovina. The second proposed witness – Witness B – was a forward air controller who engaged in intelligence-gathering, helped select bombing targets and assisted in guiding NATO aircraft to identified targets. Neither of these individuals was present during the hostage-taking incident. …
[24] Both Witnesses A and B expressed concerns that their testimony might include “potentially injurious” or “sensitive” information concerning Canada’s international relations, national defence or national security, within the meaning of s. 38 of the Canada Evidence Act, R.S.C. 1985, c. C-5 (the CEA). When notice of these concerns was provided to the Attorney General of Canada in accordance with s. 38.01(1) of the CEA, the Attorney General declined to authorize the disclosure of Witness A’s and B’s information. The appellant then applied to the Federal Court for an order authorizing Witnesses A and B to testify without restriction at his criminal trial and permitting the entirety of their proposed evidence to be disclosed. The Attorney General opposed this application and moved for directions from the Federal Court.
[73] There are two bases for the appellant’s argument that the trial judge erred by refusing to grant a stay of the proceedings on the ground of a violation of the appellant’s s. 7 Charter rights. First, the appellant attacks the Disclosure Process itself, describing it as “unprecedented and manifestly unfair”. He complains that neither he nor anyone who represented his interests was permitted to participate in the examinations of Witnesses A and B in the Federal Court disclosure proceedings, and no opportunity was afforded to his counsel to provide follow-up questions to be posed to the witnesses by examining counsel.
[74] Second, the appellant argues that the form and manner of the presentation of Witness A’s and Witness B’s evidence at trial as mandated by the Disclosure Rulings – the reading of excerpts from the redacted transcripts of their testimony to the jury in lieu of calling these witnesses to provide viva voce evidence – breached his s. 7 Charter rights. He also claims that the prejudicial effect of his inability to compel the oral evidence of these witnesses was illustrated, and exacerbated, by Crown counsel’s closing address to the jury, during which Crown counsel sought to impeach the reliability and credibility of Witnesses A and B by inviting the jury to compare their testimony as read to the jury with the “live” evidence of Crown witnesses who actually testified at trial.
[83] Unquestionably, the method of examination of Witnesses A and B under the Disclosure Process was far from ideal, involving as it did a filter between the appellant’s counsel and the witnesses and a proscription on the direct participation of the appellant’s counsel in the examination process. That said, it is my opinion that the appellant cannot rely on a challenge to the fairness of the Disclosure Process itself to support his claim in this court that a stay of the prosecution should have been granted due to the alleged infringement of his s. 7 Charter rights. I say this for several reasons.
[85] Ultimately, the Disclosure Process was authorized by consent court order of the Federal Court. Under that order, the Disclosure Process involved examinations of Witnesses A and B based on areas of questioning identified by the appellant’s counsel. In addition, the order required that while examining counsel questioned the witnesses, the appellant’s counsel “will remain available to provide further explanations on relevancy and suggestions as to possible areas of questioning”. The appellant thus participated, through counsel, in the design and approval of the Disclosure Process of which he now complains. Although the appellant’s counsel did not personally conduct the examinations in question, they had a pivotal role throughout.
[92] … [F]our judges of courts that are experienced in dealing with national security and national defence issues evaluated the fairness of the Disclosure Process and the nature and sufficiency of the information authorized for disclosure. They unanimously held that the information to be disclosed was fair and protective of the appellant’s interests to the extent possible, given the nature of the information at issue, the defences sought to be raised by the appellant at his criminal trial, and the urgency of the situation. .. [L]eave to appeal that determination to the Supreme Court of Canada was refused.
[108] There is no doubt that it would have been preferable if the defence had been able to call Witnesses A and B to testify at trial. An accused’s rights to a fair trial and to make full answer and defence are principles of fundamental justice protected by s. 7 of the Charter. They encompass the right to defend against “all of the state’s efforts to achieve a conviction” (R. v. Rose, [1998] 3 S.C.R. 262, at para. 103) and to have .the opportunity adequately to state [one’s] case. (R. v. Seaboyer; R. v. Gayme, [1991] 2 S.C.R. 577, at para. 32).
[109] However, these fundamental rights are not absolute. The jurisprudence of the Supreme Court of Canada recognizes that national security considerations can justify limitations on the extent and form of disclosure of confidential information to affected individuals. Moreover, s. 7 of the Charter does not include a guarantee that evidence may be tendered at a criminal trial in any particular form. …
[110] I am satisfied that adequate measures were found in the context of this unusual case to respect the appellant’s s. 7 Charter rights. As a result, there is no basis for appellate interference with the trial judge’s discretionary decision to refuse the extraordinary remedy of a stay of the proceedings under s. 24(1) of the Charter based on the appellant’s s. 7 claim. 
Canada, Court of Appeal for Ontario, Ribic case, Judgment, 24 November 2008, §§ 23–24, 73–74, 83, 85, 92 and 108–110, per Cronk J.A.
[emphasis in original; footnote in original omitted]