"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," Nadim Houry, deputy Middle East and North Africa deputy director at Human Rights Watch, said in a statement Thursday from Beirut.
Human Rights Watch said it visited with Gadhafi's son, former intelligence chief Abdullah Senussi and other former high-ranking officials at their respective detention facilities. The rights group said Gadhafi and Senussi said they didn't have lawyers representing them and others said they didn't have legal counsel during interrogations.
"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," Houry said.
Senussi and Saif al-Islam are accused of committing crimes against humanity during Libya's civil war in 2011. Moammar Gadhafi died after falling into rebel hands near the end of the conflict.
The International Criminal Court is investigating war crimes cases against former Libyan officials. Libya says it has the right to try them at home so long as the courts are open and functioning.