Trial court judges were fully entitled to infer the late Abdelbaset al-Megrahi was involved in the Lockerbie bombing, appeal judges have been told.
Advocate depute Ronald Clancy, for the Crown, said Megrahi's use of a false passport to travel to Malta - from where the plane carrying the bomb left just before the atrocity - taken along with other evidence, combined to form a pattern that suggested his involvement.
The bombing of Pan Am flight 103, travelling from London to New York on December 21 1988, killed 270 people in Britain's largest terrorist atrocity.
Former Libyan intelligence officer Megrahi, who was found guilty in 2001 of mass murder and jailed for life with a minimum term of 27 years, was the only person convicted of the attack.
A third appeal against his conviction began on Tuesday at the High Court in Edinburgh sitting as the Court of Appeal.
Megrahi's trial was held at a special Scottish court sitting at Camp Zeist in the Netherlands.
Mr Clancy said a number of factors suggested his involvement, including his use of a false passport.
He told the court: "There is a significant chapter of evidence which supports the identification and indeed involvement of Mr Megrahi in the conspiracy and that is his use of the false passport at a critical time, he was issued with this false passport in 1987, in the course of 1988 it was used only once, for the trip to Malta the day before the plane departed with the bomb and he returned to Tripoli using the same passport shortly after the plane left Luqa carrying the bomb , the passport was never used again.
"From the evidence about the passport and the other incriminating evidence it was possible to infer that Mr Megrahi's visit to Luqa on that date was connected with the planting of the device.
"We say that was an entirely legitimate inference to draw, certainly well within the range of inferences open to a reasonable jury."
He said the trial court was "fully entitled" to make such inferences.
An appeal against Megrahi's conviction was lodged after the Scottish Criminal Cases Review Commission (SCCRC) referred the case to the High Court in March, ruling a possible miscarriage of justice may have occurred.
Judges then granted his son, Ali al-Megrahi, permission to proceed with the appeal in relation to the argument that "no reasonable jury" could have returned the verdict the court did, and on the grounds of non-disclosure of documents by the Crown.
Claire Mitchell QC, representing the Megrahi family, said on Wednesday that the case against him hangs on the date of purchase of the clothing later found in a suitcase containing the bomb and whether it was December 7 1988 or another date.
Mr Clancy said the Crown never said it was "December 7 or bust" .
"It was not the Crown position that Mr Megrahi could not have been the purchaser if the purchase occurred on a different day," he said.
While there is no record of him being in Malta on November 23, another date suggested for when the clothing was purchased, he said there was no evidence that categorically excluded Megrahi's presence in Malta on November 23 or any other date in November or December.
He told the court that in 2007 it was established Megrahi, who held a post as head of airline security, could move in and out of Malta without leaving a trace by wearing a Libyan Airlines uniform.
Ms Mitchell said on Wednesday that evidence in relation to identification was of "poor quality" and the dock identification, when shopkeeper Tony Gauci said Megrahi resembled the man who bought the clothing was "virtually of no value".
Mr Clancy said that ignores the "important point" that the dock identification was "simply the last of a series of consistent resemblance identifications going back to February 1991".
He said the trial court was "fully entitled to conclude that Tony Gauci's identification evidence was well above the base line of quality require".
The appeal, which is taking place virtually, is being heard before five judges including Lord President Lord Carloway.
Megrahi's first appeal against his conviction was refused by the High Court in 2002 and was referred back five years later after an SCCRC review.
He abandoned this second appeal in 2009, shortly before his release from prison on compassionate grounds while terminally ill with cancer.
Megrahi returned to Libya and died in 2012.
The hearing continues.