Human Rights Watch (HRW) issued a statement on Thursday calling on the Lebanese authorities to immediate release Hannibal Gaddafi, who has been held in pre-trial detention for 10 years.

HRW reported that Gaddafi, son of former Libyan leader Muammar Gaddafi, was detained by Internal Security Forces in December 2015 “on apparently unsubstantiated allegations that he was withholding information about the disappearance of Lebanese cleric Moussa al-Sadr.” Al-Sadr, a highly revered figure in Lebanon, disappeared on August 31, 1978, after meeting with Muammar Gaddafi. Hannibal Gaddafi was two years old at the time.

Researchers interviewed Hannibal and his lawyer in prison and learned that he is currently being held in a windowless, but ventilated, underground cell. Hannibal told HRW that, while there is sufficient food and “basic health care,” he “experiences systematic weakness due to malnutrition and vitamin deficiency.” He also highlighted how “long term isolation,” no sunlight, and “lack of regular access to his family,” negatively impact his mental health.

He reported that his physical health has also “deteriorated” due to physical torture he endured when he was “initially kidnapped along the Syrian border” in 2015.

The Beirut Bar Association reported poor conditions in Lebanese detention centers and a significant backlog, with “more than 80 percent of prisoners … yet to be sentenced”

HRW previously petitioned several ministers and government officials, calling for Gaddafi’s release. However, the organization reportedly did not receive any responses.

International law requires that strict due process be followed during detentions. This includes, among other things, transparency around the reasons for an arrest, “regular judicial rulings on the legality of detention,” trials within reasonable timeframes, and “regular opportunities to challenge the lawfulness of a long-term detention.” Article 9 of the International Covenant on Civil and Political Rights and Lebanon’s penal code stipulate that failure to adhere to due process renders a detention arbitrary and unlawful.

HRW Lebanon researcher Ramzi Kaiss commented: “Gaddafi’s case is emblematic of a fractured judicial system that has lacked independence and is susceptible to political interference by Lebanon’s powerful factions … Lebanese authorities should put an end to Gaddafi’s near decade-long detention and release him immediately.”

HRW reiterated its call for Gaddafi’s immediate release and adherence to the law.