Hannibal Gaddafi, son of the late Libyan leader Muammar Gaddafi, has been moved from a Lebanese prison to a hospital in "critical condition," Dubai-based Al-Hadath TV reported on Sunday.

Gaddafi went on hunger strike last month in protest at his incarceration without trial since 2015.

Citing unidentified sources, Al-Hadath said he had suffered a sharp drop in his blood sugar level.

Gaddafi has been charged in Lebanon with concealing information about the fate of Imam Musa al-Sadr, a Lebanese Shiite Muslim cleric who disappeared while on a trip to Libya in 1978.

Muammar Gaddafi was captured and killed by rebels in 2011.