They believe the two suspects acted along with Abdelbaset al-Megrahi – the only person to have been convicted of the atrocity.
The BBC understands the pair are Mohammed Abouajela Masud and Abdullah al-Senussi.
A total of 270 people died when the Pan Am 103 flight was blown up on the evening of 21 December 1988.
The flight was on its way from London to New York when it exploded above Lockerbie, in southern Scotland, killing everyone on board and 11 people on the ground.
Senussi was the brother-in-law and intelligence chief of former Libyan dictator Colonel Gaddafi. He is currently awaiting execution in a Libyan jail.
Masud is reported to be serving a prison sentence in Libya for bomb making.