Libyan supporters of Gaddafi-era intelligence chief protest in Tripoli

Libyan relatives and supporters of Muammar Gaddafi's intelligence chief, jailed for his alleged role in the brutal crackdown during the 2011 uprising, protested in Tripoli on Saturday to demand his release.

Abdullah al-Senussi, a brother-in-law of longtime dictator Gaddafi, was sentenced to death in 2015 - along with Libyan leader's son, Seif al-Islam - following a trial condemned by the United Nations as "seriously" flawed.

Several dozen relatives and members of Senussi's tribe, the Magerha, held a demonstration in central Tripoli to demand his release over health concerns.

"The law and medical reports support our legitimate demand," said one protester, Mohammad Amer, according to AFP.

In a statement, the Magerha said his liberation would "contribute to and consolidate national reconciliation" following years of conflict.

The rare protest comes just over a month after the release on health grounds of Abuzeid Dorda, Gaddafi's head of foreign intelligence who was sentenced at the same time as Senussi.

Supporters held up photos of Senussi behind bars and placards reading "Freedom to prisoners. Yes to national reconciliation".

Senussi was extradited in September 2012 by Mauritania, where he had fled after Gaddafi was overthrown and killed.

He and Saif Islam had been the subject of an International Criminal Court arrest warrant for suspected war crimes during the 2011 uprising, which in 2013 gave Libyan authorities the green light to put him on trial.

He is being held in the capital, along with some 40 other senior officials from the Gaddafi regime, including the dictator's last Prime Minister Baghdadi al-Mahmoudi.

Seif al-Islam was captured and imprisoned by an armed group in the northwestern city of Zintan and sentenced by a Tripoli court in absentia.

The group announced his release in 2017 but it was never confirmed and his fate remains unknown.