Former justice minister Kenny MacAskill “should be investigated by the authorities” over revelations in his new book about the Lockerbie bombing.

The call came from the leader of the Scottish Liberal Democrats Willie Rennie MSP after the Sunday Herald revealed that a section of Mr MacAskill’s book “might” constitute a breach of the Official Secrets Act.

Scottish Conservative MSP Douglas Ross, who is the shadow cabinet secretary for justice, said “questions need to be answered”.

Read more: Revealed - MacAskill may have breached Official Secrets Act over Lockerbie

In Mr MacAskill's book, The Lockerbie Bombing: The Search for Justice, which is due to be released on Thursday, he reveals details of a classified document which implicates the terror group the Popular Front for the Liberation of Palestine-General Command (PFLP-GC) in the Lockerbie bombing carried out on December 21, 1988.

The document was the subject of a legal wrangle during Lockerbie bomber Abdelbaset al-Megrahi second appeal against conviction.

The Scottish Criminal Cases Review Commission (SCCRC) referred the case to the High Court on the basis that there may have been a miscarriage of justice.

The Herald: imgID67029546.jpg-pwrt3.jpg

That conclusion was reached after the SCCRC team that investigated Megrahi’s conviction discovered the existence of the document during their four-year probe which concluded in 2007.

Their 800-page report explains that their investigative team was allowed to access the document in Dumfries police station but they were prevented from removing the notes they made on it and the document itself.

The SCCRC was only able to access the document after signing up to a special agreement not to divulge the contents and was told by the Crown that “a conclusion was reached that the documents did not require to be disclosed in terms of the Crown’s obligations”.

Read more: Campaigners - MacAskill has called into question Megrahi's conviction

When Megrahi’s defence team pushed for the recovery of the information the Lord Advocate took the view that it would be appropriate to disclose the document.

However, the Advocate General, representing the UK Government, produced a public interest immunity (PII) certificate signed by then Foreign Secretary David Miliband, which blocked the disclosure on the grounds of national security.

A spokeswoman for the FCO has confirmed that “the [PII] certificate is still active” and “if the material protected by the certificate were disclosed, it might constitute a breach of the Official Secrets Act”.

The Herald:

Willie Rennie said: “Kenny MacAskill should be investigated by the authorities.

“His cavalier approach to justice has left many casualties in its wake. He should not be profiting from any breach of the Official Secrets Act.”

Scottish Conservative shadow cabinet secretary for justice, Douglas Ross, added: “Questions need answered as to whether he has broken the Official Secrets Act.”

Read more: Kenny MacAskill secures deal to write Lockerbie book

A spokesman for the Foreign Office declined to offer further comment yesterday but it is understood officials are seeking legal advice.

Victoria Gilder, publicity director at Biteback, the publisher of Mr MacAskill’s book said the former justice minister “can’t comment”.