CAIRO (AP) — Seif al-Islam Gadhafi, the son and one-time heir apparent of Libya ’s late dictator Moammar Gadhafi, was killed in the northern African country, Libyan officials said Tuesday.

The 53-year-old was killed in the town Zintan, 136 kilometers (85 miles) southwest of the capital, Tripoli, according to two Libyan security officials in western Libya. The circumstances of his death were not immediately clear.

The officials spoke on condition of anonymity because they were not authorized to brief the media.

Khaled al-Zaidi, a lawyer for Seif al-Islam, confirmed his death on Facebook, without providing details.

Abdullah Othman Abdurrahim, who represented Gadhafi in the U.N.-brokered political dialogue which aimed to resolve Libya’s long-running conflict, also announced his death on Facebook.

Abdurrahim didn’t provide further details, but Libyan news outlet Fawasel Media cited him as saying that armed men killed Seif al-Islam in his home. The outlet reported that prosecutors were investigating the killing.

Born in June 1972 in Tripoli, Seif al-Islam was the second-born son of the longtime dictator. He studied for a PhD at the London School of Economics and was seen as the reformist face of the Gadhafi regime.

Moammar Gadhafi was toppled in a NATO-backed popular uprising in 2011 after more than 40 years in power. He was killed in October 2011 amid the ensuing fighting that would turn into a civil war. The country has since plunged into chaos and divided between rival armed groups and militias.

Seif al-Islam was captured by fighters Zintan late in 2011 while attempting to flee to neighboring Niger. The fighters released him in June 2017 after one of Libya's rival governments granted him amnesty. He had since lived in Zintan.

A Libyan court convicted him of inciting violence and murdering protesters and sentenced him to death in absentia in 2015. He was also wanted by the International Criminal Court on charges of crimes against humanity related to the 2011 uprising.

In November 2021, Seif al-Islam announced his candidacy in the country’s presidential election in a controversial move that was met with outcry from anti-Gadhafi political forces in western and eastern Libya.

The country’s High National Elections Committee disqualified him, but the election wasn’t held over disputes between rival administrations and armed groups that have ruled Libya since the bloody ouster of Moammar Gadhafi.