Tripoli - Human Rights Watch called on Libyan authorities on Thursday to provide proper defence counsel to slain dictator Muammar Gaddafi's son and top aides to ensure they receive a fair trial.
The New York-based watchdog said that during visits by its staff last month, both Seif al-Islam Gaddafi and former spy chief Abdullah Senussi had complained that they had no representation at all during interrogations and pre-trial hearings in their prosecution for gross abuses during the 2011 uprising.
Former premiers Al-Baghdadi al-Mahmudi and Bouzid Dorda said they did have lawyers but they had been unable to meet them in private to prepare their defence and had been denied access to the evidence against them.
HRW Middle East and North Africa deputy director Nadim Houry said: "The Libyan government should make greater efforts to ensure these detained former officials have adequate legal counsel and the opportunity to defend themselves fairly before a judge.
"The prosecution of these men will be no more credible than a kangaroo court if the authorities fail to provide these men with basic due process rights."
HRW called on Libyan authorities to investigate allegations made by Dorda at a court session last month that he had been beaten and wounded in his prison cell.
"Under these circumstances, it's hard to imagine how any of these men can have a fair trial in Libya," Houry said.
The four are among a total of 37 former Gaddafi regime officials who are to stand trial on charges including murder, kidnapping, complicity in incitement to rape, plunder, sabotage, embezzlement of public funds and acts harmful to national unity.
No trial date was set at the third and final pre-trial hearing.
The International Criminal Court in May last year rejected a request by Libya to try Seif al-Islam, Gaddafi's former heir apparent, on war crimes charges because of doubts he would receive a fair trial.
Tripoli has appealed the decision but Seif is still wanted for trial by the ICC on charges of war crimes and crimes against humanity during the 2011 uprising that ended his father's 42-year rule.