Donald Trump has been urged to declassify US files on the Lockerbie bombing.
A lawyer who represented the British victims killed in the attack called on the US president to release the documents, insisting the families “deserve transparency, truth and answers”.
Mr Trump has already moved to declassify files related to the killing of John F Kennedy, Robert Kennedy and Martin Luther King Jr.
Professor Peter Watson has now asked Mr Trump to make public the documents related to the bombing of Pan Am flight 103.
Prof Watson served as secretary for the Lockerbie Disaster Group and made the request in a letter to Matthew Palmer, the charge d’affaires at the US Embassy in the UK.
On 21 December 1988, the flight, which was carrying 259 passengers and crew to the US, was blown out of the sky above the Scottish town of Lockerbie.
All of those on board were killed along with 11 people on the ground.
No public inquiry into the bombing has been held and Prof Watson said declassifying the documents would help “fill the vacuum of understanding” around the tragedy.
Former Libyan intelligence officer Abdelbaset al Megrahi remains the only person to ever be convicted over the attack.
He was sentenced to life in prison but was released in 2009 on compassionate grounds after being diagnosed with cancer. He died in 2012.
Another Libyan man, Abu Agila Masud, is alleged to have made the bombs and faces trial in the US in May on three charges, all of which he denies.
Prof Watson said: “Nearly four decades later, as new trials and investigations continue, the pursuit of truth and justice for the victims and their families endures.
“The families of the victims are entitled to know as much as possible about what happened on the night of the bombing, and we know there are documents held by the US and UK intelligence services that fill the vacuum of understanding that remains today.
“We have seen a move from President Trump to declassify a number of federal secrets, and we believe Lockerbie should be next.”
Read more from Sky News:
Pope Francis admitted to hospital
William and Kate mark Valentine’s Day
Man guilty of murder of Irish backpacker in India
Prof Watson added: “The families have waited far too long. They deserve transparency, truth and answers.”
In August 2003, Libya accepted blame for the bombing and agreed to compensate victims’ families $2.7bn (£2.1bn).