Lagos - The African Commission on Human and People's Rights is appealing to President Goodluck Jonathan to halt resumed executions.
Four men have been hanged and a fifth is in imminent danger of being shot.
Human rights lawyer Femi Falana called Thursday's request "a landmark decision" following his petition to the Gambia-based commission on behalf of Nigeria's Socio-Economic Rights and Accountability Project.
State governors signed five death warrants and prison authorities hanged four convicted murderers on 24 June, ending a seven-year moratorium. They acted after Jonathan ordered governors to sign death warrants.
A fifth man was not executed because his sentence is to be shot by firing squad.
All were sentenced under the former military dictatorship notorious for torturing confessions from suspects.
More than 1 000 people are on death row in Nigeria.