Scotland's justice secretary and top law officer have been reported to a worldwide organisation of prosecutors following concerns about the handling of Lockerbie bombing inquiries.

Pressure group Justice for Megrahi wants the International Association of Prosecutors (IAP) to look at Kenny MacAskill and Lord Advocate Frank Mulholland's "objectivity and independence" in dealing with allegations against the Crown Office and police.

The move is part of a wider campaign for an independent inquiry into the conviction of Abdelbaset al Megrahi for the bombing of Pan Am flight 103 over Lockerbie in December 1988.

Justice for Megrahi revealed the decision to report the senior figures on the day MSPs at Holyrood's Justice Committee consider its ongoing petition.

In a submission to the committee, group secretary Robert Forrester stated: "This latest international complaint makes it even more important that our petition remains a live issue within the Scottish Parliament. Not only are the Crown Office and police engaged in acting in their own interest by investigating the eight criminal allegations we have made against them and others but... the Crown office has, without explanation, ordered the police to stop investigating three of the most central allegations.

"As the 25th anniversary of the Lockerbie tragedy approaches, the Scottish Government has apparently washed its hands of any responsibility for further action in relation to our concerns. It is therefore of paramount importance that this affair remains a live issue within the Scottish Parliament and that the Justice Committee continues in its duty to 'scrutinise the policies and performance of the Scottish Government and its agencies in matters related to justice' and ensures that this massive stain on our justice system is not buried in the cause of the unaccountable self-interest of our major prosecution agencies."

The IAP, formed as a non-political organisation in 1995, aims to raise standards of professional conduct and ethics for prosecutors across the world. It can consider whether the complaint amounts to a breach of its standards.