The Scottish government said its “thoughts and sympathies” were with the victims of the Lockerbie bombing, 22 years since the atrocity.
Pan Am Flight 103 exploded over the Scottish town on December 21, 1988, killing 270 people in the air and on the ground.
Abdelbaset Ali Mohmed Al Megrahi, the Libyan convicted of the bombing, remains alive in Tripoli 16 months after being released from jail on compassionate grounds.
Mr Megrahi, who has prostate cancer, was freed from Greenock prison in August last year with an estimated three months to live.
Many relatives condemned the release while others continue to raise questions over Mr Megrahi’s conviction.
Scottish Justice Secretary Kenny MacAskill agreed to the compassionate release in August last year.
A Scottish government spokes-man said: “Our thoughts and sympathies are with all those affected by the events of that terrible night, but most especially the families and relatives wherever they are in the world.
“Scotland’s justice system has been dealing with the Lockerbie atrocity for 22 years, and in every regard the due process of Scots Law has been followed – in terms of the investigation, prosecution, imprisonment, rejection of the prisoner transfer application and granting of compassionate release.”
Pamela Dix, from Surrey, has spent the last 22 years fighting for a full independent inquiry into events surrounding the bombing, which killed her brother Peter.
“Twenty-two years seems like yesterday in some ways and in other ways it feels like a lifetime ago,” she said.
“The number of years is meaningless in a way as the loss of those lives does not diminish. They have not had the chance to live their lives.
“It was unacceptable then and it is unacceptable now, that will never change.” Peter Dix, 35, was travelling to New York with his job as a management consultant when he died along with 258 other passengers.
A further 11 people died on the ground in the disaster, four days before Christmas.
The majority of those who died in the Lockerbie bombing were American citizens, though the 11 killed on the ground were all British.
The remaining victims came from 19 other countries, including France, Germany, India, Sweden, Australia and Japan.
There are those who believe Mr Megrahi is innocent and campaigners in the UK continue to call for an independent inquiry into the bomber’s conviction.
Jim Swire, part of the Justice For Mr Megrahi campaign group, told MSPs at Holyrood last month: “I now believe that Scottish justice’s verdict on this man is not safe, it must be re-examined.”
“And until it is, the name of Scottish justice will lie in the gutter.”
The decision to release Mr Megrahi prompted political anger from the US and UK Administrations and the SNP’s opponents at Holyrood.
Timeline of events
Here are the key dates leading up to and since the controversial decision to allow convicted Lockerbie bomber Abdelbaset Ali Mohmed Al Mr Megrahi to return to Libya.
December 21, 1988: 270 die as Pan Am flight 103 explodes over the Scottish town of Lockerbie.
January 31, 2001: Following a trial at Camp Zeist in the Netherlands, Mr Megrahi is found guilty of mass murder and jailed for life.
March 14, 2002: Mr Megrahi loses an appeal against the conviction.
August 19, 2003: Libya accepts the blame for the Lockerbie bombing and agrees to compensate the victims’ families.
September 23, 2003: The Scottish Criminal Cases Review Commission is asked to investigate Mr Megrahi’s conviction.
March 2004: Prime Minister Tony Blair offers Colonel Muammar Gaddafi “the hand of friendship” following talks with the Libyan leader in a tent outside Tripoli.
May 2007: Talks between Mr Blair and Col Gaddafi result in a memorandum of understanding. Negotiations begin on a prisoner transfer agreement.
Signing of an exploration and production sharing agreement (EPSA) between oil giant BP and the Libyan government.
June 2007: Scotland’s First Minister Alex Salmond raises concerns with Mr Blair that the deal could lead to Mr Megrahi being returned to Libya. The UK government agrees to seek a PTA that excludes Mr Megrahi.
The SCCRC recommends that Mr Megrahi is granted a second appeal against his conviction.
October-November 2007: Discussions between BP and UK Justice Secretary Jack Straw. BP raises concerns about the effect of the slow progress of the PTA negotiations on commercial interests, including the ratification of the BP exploration agreement.
December 19, 2007: Mr Straw writes to his Scottish counterpart Kenny MacAskill to inform him the UK government decided not to exclude Mr Megrahi from the PTA.
January 2008: The BP exploration deal is ratified by the Libyan government.
September 2008: Mr Megrahi is diagnosed with terminal prostate cancer.
November 2008: Signing of the PTA.
April 29, 2009: The PTA comes into force, allowing Mr Megrahi to apply to serve the rest of his sentence in a Libyan jail. He must drop his appeal against his conviction for any PTA to take place.
May 5, 2009: The Libyan government submits a formal application to the Scottish government for Mr Megrahi’s transfer under the PTA.
July 24, 2009: The Libyan government submits an application to the Scottish government for Mr Megrahi’s release on compassionate grounds.
August 9, 2009: In a communication to the Scottish government, US authorities say a conditional release on compassionate grounds was a “far preferable alternative” to Mr Megrahi’s transfer back to a Libyan jail.
August 14, 2009: US Secretary of State Hillary Clinton urges Mr MacAskill not to release Mr Megrahi.
August 18, 2009: Mr Megrahi’s bid to drop his second appeal against his conviction is accepted by judges in Edinburgh.
August 20, 2009: Having rejected Libya’s application under the PTA, Mr MacAskill announces his decision that Mr Megrahi is to be returned to his home country on compassionate grounds.
August 21, 2009: The UK and the US condemn the “hero’s welcome” given to Mr Megrahi as he arrives in Tripoli to cheering crowds.
August 22, 2009: Libyan television shows pictures of Col Gaddafi meeting Mr Megrahi and praising Prime Minister Gordon Brown and the UK government for their part in securing his freedom.
August 25, 2009: Mr Brown says he was “repulsed” by Mr Megrahi’s welcome in Libya and insists the British government had no role in the decision to free him.
September 2, 2009: The Scottish government suffers a defeat in Parliament over its handling of the Lockerbie case.
September 5, 2009: Mr Straw acknowledges that the prospect of trade and oil deals with Libya played “a very big part” in his decision to include Mr Megrahi in the PTA.
September 26, 2009: Col Gaddafi said no deal was done to secure the release of the man convicted of the Lockerbie bombing.
July 15, 2010: Hillary Clinton says she will look into claims by a group of senators that BP lobbied the government to release Mr Megrahi in order to smooth an oil deal with Libya.
July 20, 2010: On his first visit to Washington as Prime Minister, David Cameron tells US media that Mr Megrahi should have died in jail. He asks Cabinet Secretary Sir Gus O’Donnell to review the government’s documentation on his release.
July 22, 2010: The Scottish government declines a request from US senators that Mr MacAskill appear at a hearing of the Foreign Relations Committee on the Lockerbie controversy. Mr Straw declines the same request the following day.
July 29, 2010: Senator Robert Menendez says the Committee will send members to the UK to question witnesses.
August 20, 2010: On the first anniversary of Mr Megrahi’s release, US senators say a “cloud of suspicion” remains over the decision to return him to Libya and call for an inquiry.
September 16, 2010: Scottish justice officials hold a meeting with an American delegation investigating Mr Megrahi’s release.
September 29, 2010: Senate Foreign Relations committee hears that a review of US government records found no information about BP attempting to influence the release of the Lockerbie bomber.
October 19, 2010: More than 1,200 people back an independent inquiry into Mr Megrahi’s conviction in a petition lodged at the Scottish Parliament.
December 9, 2010: There are claims that the Lockerbie bomber is close to death after a rapid deterioration in his health.