Hannibal Gaddafi, the son of former Libyan leader Muammar Gaddafi, began a hunger strike in Lebanon, where he has been held in detention since 2015, his lawyer said.
Hannibal began the hunger strike on Friday to protest his prolonged detention without trial, his lawyer Paul Romanos said in comments to the media, adding that his health condition was deteriorating.
Efforts were being made to secure Hannibal's release by engaging with international human rights organisations and legal and political channels, Romanos added.
Hannibal has been detained in Lebanon for over eight years without trial after being abducted by Lebanese militants who demanded information about the fate of Lebanese Shia cleric Imam Moussa al-Sadr - who disappeared during a visit to Libya in 1978.
The Lebanese Amal Movement blames the disappearance of Sadr on the Gaddafi regime.
Conflicting about the Shia leader's fate had emerged in the past and some of it has indicated that the late Libyan dictator had ordered his killing.
Sadr was last seen in Italy boarding a plane bound for the Libyan capital Tripoli.
Calls for Hannibal's release
A statement from the Gaddafi family condemned Hannibal's detention, slamming it as a crime and vowing to take action to ensure his release.
Mohammed Bayou, a former Gaddafi-era official, also voiced support for Hannibal, asserting that he was "unjustly detained" and calling for Libyan authorities to secure his release.
A pro-Gaddafi Facebook page attributed to the "Libyan embassy in Syria", which claimed that the embassy had been in contact with the Lebanese foreign ministry regarding Hannibal's detention and health conditions.
The consul, Mohammed Shaaban, holds the Amal Movement accountable for Hannibal's safety, according to the statement.