The United States on Monday unsealed criminal charges against a third alleged conspirator in the 1988 bombing of Pan Am Flight 103 over Lockerbie, Scotland, that killed 270 people, mostly Americans.

The suspect, Abu Agila Mohammad Masud Kheir Al-Marimi, a former senior Libyan intelligence official, was charged with two criminal counts related to the bombing, according to Reuters.

US Attorney General William Barr said he is in Libyan custody and US officials are hopeful that Libya will allow Masud to be tried in the United States.

British newspaper The Sunday Times said Libyan authorities were pondering extradition of Masud who is now serving ten years' prison term in Tripoli.