It's been three decades since Pan Am flight 103 blew up over the town of Lockerbie.

Only one man has ever been brought to justice for the attack, which claimed 270 lives.

The plane, travelling from London to New York, exploded 31,000 feet above Lockerbie 38 minutes into its journey on December 21, 1988.

Abdelbaset Ali Mohmed Al Megrahi was jailed for 27 years in 2001 before being released in 2009 on compassionate grounds as he battled cancer, shortly after abandoning his appeal.

His supporters, though, to continue to contest his conviction and hope he will one day be cleared.

They include relatives of Lockerbie victims, including Dr Jim Swire, whose daughter Fiona died in the bombing.

Al Megrahi's conviction is currently being studied by the Scottish Criminal Cases Review Commission (SCCRC).

His family filed an application to have his conviction overturned in July last year.

In May this year, the SCCRC announced that it would carry out a full review and decide whether an appeal against the conviction could be made.

Speaking at the time, the family's solicitor Aamer Anwar said: "When Mr Megrahi abandoned his appeal it simply didn't make sense.

"He had maintained his innocence until his dying breath, so nobody could understand why all of sudden he would drop it.

"There have always been allegations that the UK Government applied pressure to him and others, including the Libyan government, over the appeal.

"That is a matter that will be addressed at a later stage.

"But the commission has accepted there was a genuine and reasonable belief by Mr Megrahi that unless he dropped his appeal then he would simply die in prison in Scotland."

They're expected to make their ruling early in 2019.

In November, a four-year Police Scotland probe, known as Operation Sandwood, into the handling of the bombing investigation and prosecution found no evidence of criminality.

It came after nine allegations were made by the Justice for Megrahi campaign group.

They welcomed the police report and said the findings will be of importance to many of the issues being considered by the SCCRC

The group said: "The Operation Sandwood investigation has resulted in a seminal report which has examined many of the controversies which have arisen over the past 30 years.

"We believe that Police Scotland conducted their enquiry with thoroughness and integrity and we thank them for the work they have carried out."

Materials gathered during Operation Sandwood have now been handed over to the Crown Office.

A Crown Office spokesman said: "The Lord Advocate has been informed by the chief constable of the findings of the Operation Sandwood investigation and of the chief constable's conclusion, informed by the advice of independent senior counsel, that no evidence of any criminality was found.

"The findings contain material relevant to the live investigation into the Lockerbie bombing and to the SCCRC consideration of the case.

"On that basis, the documents have been passed to the Crown Office and Procurator Fiscal Service team dealing with the live investigation so that they can be given appropriate consideration."

November 14, 1991: US and Britain accuse two Libyans, Abdelbaset Ali Mohmed Al Megrahi and Al Amin Khalifa Fhimah, of the bombing. Libya denies any involvement.

May 3, 2000: Lockerbie trial opens in Camp Zeist in the Netherlands under Scots law. The two men are charged with conspiracy, murder and contravention of the Aviation Security Act 1982.

January 31, 2001: Al Megrahi is found guilty of mass murder and sentenced to life, with a minimum term of 27 years. Fhimah is found not guilty and freed.

January 23, 2002: Al Megrahi's appeal begins before a panel of five judges at Camp Zeist.

March 14 2002: The judges uphold the conviction of Al Megrahi.

September 23, 2003: Lawyers for Al Megrahi apply to the Scottish Criminal Cases Review Commission (SCCRC), the body which investigates alleged miscarriages of justice, for a review of his sentence and conviction.

June 28, 2007: SCCRC issues judgement following its review of the Al Megrahi case. It was referred by the commission to the High Court for a new appeal.

October 21, 2008: It's confirmed that Al Megrahi has been diagnosed with prostate cancer which has spread to other parts of his body and is at an advanced stage.

August 18, 2009: Al Megrahi abandons his appeal.

August 20, 2009: Al Megrahi flies home to Libya after being freed on compassionate grounds.

May 20, 2012: The death of Al Megrahi is reported in Tripoli.

February 2014: Operation Sandwood is launched by Police to investigate the conviction of Mr Megrahi. The claims made by the Justice for Megrahi campaign group, were against the police, Crown Office and forensic officials and included claims of perjury and perverting the course of justice.

June 2014: SCCRC receive another application on behalf of Mr Megrahi.

November 5, 2015: Application is rejected by the Commission after it concluded that it wasn't in the interests of justice at that time to proceed with the review.

July 2016: Representatives of Mr Megrahi's family submit a further application to the SCCRC.

May 3, 2018: The Commission decides that it is in the interests of justice to accept the current application for a full review of Mr Megrahi's conviction.

November 22, 2018: The conclusion of Operation Sandwood. Police Scotland confirms that they have found no evidence of criminality in relation to the handling of the investigation and prosecution of the Lockerbie bombing.