It comes after the Scottish Criminal Cases Review Commission last week granted an appeal into the 2001 conviction of the late Abdelbaset al-Megrahi amid concerns over a potential “miscarriage of justice”.
Dr Jim Swire, whose daughter Flora died in the tragedy, said the green light for the appeal will see Megrahi cleared. But he fears it may leave unanswered questions about what really led to Scotland’s worst terrorist atrocity.
Megrahi died in 2012 but his family are now set to pursue the appeal on his behalf.
The bombing of Pan Am Flight 103 over Lockerbie in December 1988 resulted in the deaths of 243 people on board and 16 people on the ground.
But while the US families have largely accepted the verdict, Swire and campaigners in the UK believe Megrahi’s conviction was a miscarriage of justice.
Swire said he was “euphoric” about the appeal being granted last week.
But he added: “There are only two outcomes that we desperately need from this whole sorry business.
“One is the removal of this ridiculous verdict against Megrahi. The other is the answer to the question ‘Well, who did do it?’”
Swire has long pointed to evidence from a baggage handler at Heathrow about “unaccounted for suitcases” in the container for the flight prior to the attack, as well as claims of a break-in at the airport. He said these provide an “alternative route” which could have seen the suitcase containing the bomb get on to the flight.
“There has to be a properly endowed inquiry to follow the removal of the verdict against Megrahi,” Swire added.
This must address the question of who was responsible, he added.
“It should be internationally founded. One nation’s legal system should not be the judge of a criminal case. The criminal case ought originally to have been in the international criminal court and not under Scottish law.
“To get an objective inquiry it needs to be endowed with powers that enable it to look into the materials that are still being actively hidden by the current Conservative government.”
These are documents in the National Archives, according to Swire, which have a “direct bearing” on the Lockerbie investigation.
Swire fears the fresh appeal in Scotland’s High Court won’t get to the bottom of what happened.
“I think it is likely that, because there is so much evidence against them, the prosecution will seek to allow the overturning of the verdict against Megrahi without examination of more than a tiny fragment of the evidence which was used against him.
“That would be a terrible pity, because a lot of people were culpable over the way they supplied rubbish evidence to get him convicted.”
The criminal appeal was granted on the grounds of “unreasonable verdict” and “non-disclosure”. An appeal could take up to a year to reach court.
Swire has long believed that Iran was behind the bombing, in alliance with Syrian terrorist group PFLP-GC. He claims it was an act of revenge after the US military shot down an Iranian passenger jet in July 1988, killing 290 people on board.