相关规则
Nigeria
Practice Relating to Rule 161. International Cooperation in Criminal Proceedings
Section C. Extradition of own nationals
Nigeria’s Extradition Law (1967) states:
6. Requests for surrender, and powers of Attorney-General thereon
(3) Except in so far as an extradition agreement in force between Nigeria and the requesting country otherwise provides, the Attorney-General may refuse to make an order under this section in respect of any fugitive criminal who is a citizen of Nigeria. 
Nigeria, Extradition Act, 1967, Article 6(3).