His adviser, Abdallah Othman Abdurrahim, confirmed his death in a social media post, saying that he was killed by unidentified gunmen.
Seif Al-Islam, 53, had been seen as his father’s successor.
He was arrested in November 2011 in southern Libya following a warrant by the International Criminal Court (ICC).
He was sentenced to death in 2015 after a speedy trial, but was granted amnesty.
In 2021, he announced he would run for president, but those elections were indefinitely postponed.
DID/IRN