The UK government has been accused of 'insulting' the families of victims of the Lockerbie tragedy after failing to release a secret telegram.

The accusation comes after ministers refused to reveal the contents of the message, sent to former Prime Minister John Major in 1991, claiming it would be harmful to Britain.

The telegram, sent three years after the Lockerbie bombing, contained information about the atrocity from an unnamed overseas government and is now held at the UK National Archives at Kew, west London.

An application made by The Times newspaper to view it was rejected on the basis that it would be damaging to national interests.

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The decision means the document will remain closed to the public until at least 2032.

Iain McKie, of the Justice for Megrahi group, told The Times: "It beggars belief that the UK government, after 30 years of widespread and well-founded doubts about various aspects of the Lockerbie investigation and trial, continues in its efforts to hide the truth about the tragedy.

"That they should claim to be protecting the public interest only adds insult to injury for the family and friends of the 270 souls who perished."

Robert Black, a legal expert who helped to establish the Lockerbie trial, raised concerns about a lack of transparency from successive UK governments.

The professor emeritus of Scots law at the University of Edinburgh, said: "It is extremely difficult to understand how a document dating from November 15, 1991, could still in 2019 adversely affect the national interests of the UK or its relations with the country of origin.

"Much more likely is that the contents of the documents would embarrass the UK by showing just how tenuous is the case for Libyan responsibility for the Lockerbie tragedy."

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National Archive records confirm that Mr Major received a telegram relating to the Lockerbie bombing on November 15, 1991.

A response to the request says: "In this instance, we believe the release of the information received in confidence would harm UK relations with the country which provided the information. This would be detrimental to the operation of government and would not be in the UK's interest.

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"In light of the potential harm to UK relations with the country concerned, and UK interests there, it is judged that release of the material would not be in the public interest."

Abdul Baset Ali al-Megrahi, a Libyan intelligence agent, remains the only person to be convicted in connection with the bombing.

He was found guilty after being tried under Scots law at Camp Zeist in the Netherlands in 2000. He died in 2012.