The man accused of making the bomb that detonated Pan Am Flight 103 over Lockerbie in 1988 is currently being held in the United States.
Abu Agila Mohammad Mas’ud Kheir al-Marimi is said to be the “third conspirator” behind the attack.
Some 243 passengers and 16 crew members were killed when the device, planted on the airliner, exploded at 38,000 feet.
Eleven other people were killed on the ground as debris fell on homes in the town of Lockerbie, Scotland.
The only person convicted for these atrocities was Abdelbaset Ali Mohmed al-Megrahi, who was imprisoned for life in 2001 and released on humanitarian grounds in 2009 after being diagnosed with cancer. He died in 2012.
Scottish authorities said: “The families of those killed in the Lockerbie bombing have been informed that the suspect Abu Agila Mohammad Mas’ud Kheir al-Marimi is in US custody.
“Scottish prosecutors and police, together with the UK government and their US colleagues, will continue this investigation, with the sole aim of bringing to justice those who acted with al-Megrahi.”
