Amnesty International has appealed to the Edo State Governor, Adams Oshiomhole, to rescind its decision to carry out the death sentence passed on two inmates at the state prison.
The African Commission on Human and Peoples' Rights (ACHPR) has also written to President Goodluck Jonathan, asking him to prevail on the governor to stop the execution.
Amnesty International noted that it was difficult for many accused persons to get justice in Nigeria's justice system, adding that it would not be fair to execute those who might not have received fair trials and who had been on death row for many years.
Director General of Amnesty International, Mr. Salil Shetty, who stated this Monday when he visited the offices of the Human Rights Social Development and Environment Foundation (HURSDEF) in Port Harcourt, said the body was concerned that Oshiomhole had expressed his readiness to go ahead with the execution of the two death row inmates.
Shetty said the excuse given by Oshiomhole that he would go ahead with the executions to tackle the challenge of prison congestion was not the best way of addressing the problem.
"Now the argument being given in order to proceed with the death penalty in Nigeria is that the prisons are too congested. This must be the most tragic way to addressing prison congestion.
"In the first instance, you don't have a fair trial system and people are waiting on death row without trial for a long time, and now you are going to execute the people because the prisons are too congested," he said.
He insisted that there must be a better way of addressing prison congestion than executing the people concerned, suggesting that the government could decide to commute the death sentences to prison terms instead of wasting lives.
In his address, Director General of HURSDEF, Justin Ijeomah, said his organisation had been involved in the campaign to abolish the death sentence in Nigeria as a result of studies that had shown that the country's criminal justice system could not guarantee a fair trial.
"Hence a system that seeks to take lives must give justice to the poor that cannot afford the cost of legal representation in court," Ijeomah said.
Also, ACHPR waded into the issue Monday and called on the president to prevail on the governor to stop the execution of the two convicts.
Responding to a petition sent to it by the Socio-Economic Rights and Accountability Project (SERAP), the commission said it was concerned about reports of the imminent execution of two prisoners on death row in Benin prison - Daniel Nsofor and Osayinwinde Agbomien - despite the current appeal against the death penalty.
A statement from the commission obtained by THISDAY reads: "The African Commission therefore urges the Federal Republic of Nigeria to prevail on the Edo State Government to exercise restraint, and not to execute the prisoners while their appeal is still pending in court.
"The Nigerian government is reminded that the African Commission on Human and Peoples' Rights at its 44th Ordinary Session in Abuja, Nigeria, in November 2008 adopted a resolution calling on African states, including Nigeria, that still retain the death penalty to observe a moratorium on the execution of death sentences with a view to abolishing the death penalty.
"The said resolution also forbids the application of the death penalty in conditions not respectful of the right to a fair trial guaranteed under the African Charter on Human and Peoples' Rights and other relevant international norms."