Beirut: A flamboyant son of Libya’s deposed leader Muammar Gaddafi was formally arrested and interrogated in Lebanon on Monday, accused of withholding information about the unsolved 1978 disappearance of a revered Lebanese Shiite cleric and two companions in Libya.

The formal arrest of Hannibal, Gaddafi’s youngest son, signalled an intriguing turn in a cold-case mystery that has transfixed the Shiite world for nearly four decades.

It came four days after Lebanese news services said the son had been abducted by Lebanese militants who are followers of the missing cleric, Mousa Al Sadr, one of the most respected Shiite religious figures in the Middle East.

The militants forced Gaddafi to recite a statement on television on Friday affirming the justness of their cause, then released him into the temporary custody of Lebanon’s intelligence and judicial branches, where the unsolved case of the missing cleric suddenly and unexpectedly appears to have been revived.

Details of precisely how and where Gaddafi was abducted — as well as who abducted him — remain unclear. Also unclear is the whereabouts of his wife, Aline Skaf, a Lebanese lingerie model.

The couple, once known for drama-filled debauchery and unpaid bills in European hotels, had been thought to be living in Algeria since the overthrow and death of Muammar Gaddafi during the tumultuous Libyan revolution of 2011 that ended Gaddafi’s prolonged and oppressive rule.

Lebanese news reports, quoting unidentified sources, said Hannibal Gaddafi was abducted in Syria and brought to Lebanon. Those accounts could not be corroborated.

Al Sadr, a hero of Lebanon’s poor Shiite population, disappeared in 1978 along with two Lebanese companions, Shaikh Mohammad Yaqoub and Abbas Badreddine, a journalist, during a visit to Libya at the invitation of Muammar Gaddafi, the erratic dictator who was then heavily invested in financing militant movements in the region.

Many Lebanese believe that the three visitors were secretly imprisoned and killed on Muammar Gaddafi’s orders, but their bodies were never found. Gaddafi and his subordinates denied such accusations and said the three disappeared after they had left Libya.

Hannibal Gaddafi, 40, one of at least eight children fathered by Muammar Gaddafi, would have been a toddler at the time, raising questions about what he could possibly know of the mystery.

Nonetheless, Lebanese news services reported Monday that Magistrate Zaher Hamadeh from the Justice Ministry issued a formal arrest warrant for him, after having questioned him for much of the day, on charges of withholding information about the unsolved case.

It is not known how long the Lebanese authorities intend to keep Gaddafi or whether they might extradite him to Libya, where at least three of his brothers died in the 2011 revolution and another was sentenced to death in July.

Hassan Yaqoub, a former Lebanese lawmaker who is a son of Shaikh Yaqoub, said on Monday in a telephone interview that many Lebanese had welcomed the Gaddafi’s abduction and arrest, which could provide new leads in a mystery that remains an unhealed wound.

“I don’t say that Hannibal was directly involved in this case, since he was a kid,” Yacoub said, “but he’s the son of Muammar Gaddafi, and we know how important his children were in the leadership back then.”

What is most important, he said, is that Gaddafi’s son “is now with the Lebanese authorities and the file has been reactivated.”

Details of what Gaddafi said in the interrogation were not publicly disclosed. But Yaqoub said he had learned from sources close to the investigation that Gaddafi had implicated his father’s former right-hand man, Abdel Salam Jalloud, in the case. Jalloud abandoned the Gaddafi government in August 2011, a few months before the end. His whereabouts is unknown.

According to Yaqoub, Gaddafi also revealed the names of two men who masqueraded as Yaqoub’s father and Al Sadr while staying at a Holiday Inn in Italy in the days after their visit to Libya presumably had ended. Yaqoub said these impersonators were part of an apparent plot to convey the false narrative that they disappeared after having left Libya.