Alex Salmond is set to accuse Scotland’s most senior ­prosecutor of abusing his position, resulting in bombshell evidence of government ­negligence being suppressed, the Sunday Mail can reveal.

The ex-first minister will unleash an unprecedented attack on the ­“collapsing, discredited” Crown Office after he was threatened with ­prosecution over memos and SNP texts he wanted to share with MSPs.

He will allege Scotland’s ­embattled Lord Advocate James Wolffe wrongly applied legislation which led to Parliament being blocked from evidence damaging to Nicola Sturgeon and her inner circle.

Salmond hopes to deliver the assessment to a Holyrood­ ­committee probing the Scottish Government’s ­unlawful investigation into claims of sexual harassment made against him.

Both he and Sturgeon could appear but sessions are in limbo pending a legal judgment that could impact on the ­evidence members can hear.

A source close to Salmond said: “These are threats from an unelected official citing legislation passed by this Parliament for quite different reasons. The result is information is denied to a committee of elected ­parliamentarians.

“Some of the information Alex had intended to provide was Government documents, which should have been provided to the committee in the first place but have been suppressed.

“This position is extraordinary and totally unacceptable. What is ­becoming shockingly clear is the extent to which the lines between the SNP, government and justiciary have become blurred in Scotland and that should be a huge concern to everyone.”

Wolffe is already under pressure over the “malicious prosecution” of two men who were awarded ­£10.5million in damages in relation to the ­administration of Rangers FC in 2012.

Salmond is expected to allude to the case as further evidence of a justiciary in disarray. He believes a group of figures around ­Sturgeon colluded to bring him down as part of a vendetta.

Evidence he wanted to provide is understood to include messages ­suggesting senior SNP figures were working behind the scenes to ­encourage women to make complaints, plus ­Government memos. But the ­Sunday Mail can reveal letters sent to Salmond’s lawyers warned he and MSPs receiving the information would be at risk of ­prosecution should it be divulged.

Conservative MSP Murdo Fraser said: “If a former first minister feels unable to tell the truth because he feels ­threatened by Scotland’s state ­prosecutor, we are in deeply worrying territory.

“The Lord Advocate has admitted the Crown pursued malicious ­prosecutions against innocent men.

“That concerns everyone, but we have no idea how deep this runs. Only a ­public inquiry led by a judge from ­outwith Scotland can get to the truth and restore public confidence in the Crown.”

Labour’s Jackie Baillie added: “It is in the interests of everyone that Alex ­Salmond is able to appear before the committee and give his evidence. We need to get to the truth over what went so badly wrong in this fiasco.”

Salmond is expected to target Wolfe – a member of Sturgeon’s Cabinet – and Crown agent David ­Harvie, who is chief executive of the Crown Office and Procurator Fiscal Service (COPFS).

COPFS wrote to Salmond’s legal team on September 17, 2020, ­warning it would be a criminal offence to release documents to the committee.

They wrote again on November 3 and again on December 17, going further to block information specifically requested by the committee members.

They wrote: “For you or your client to accede to the request of the clerk to the committee would require both the use and ­disclosure of said information. As such, what is proposed would amount to a clear breach of section 163 which, by reference to section 163, would amount to a criminal offence.”

The Crown added: “Any person who received such information from you or your client would also be in breach of section 162, and consequently section 163, if they use or disclose that ­information. In these circumstances, I do not consider what is proposed is acceptable.”

A COPFS spokesman said: “We engaged constructively with the ­committee and with Mr Salmond’s lawyers.

"To protect public confidence and trust it is vital that information held for the investigation and ­prosecution of crime is handled ­carefully, thoughtfully and lawfully.” Last week, the Sunday Mail revealed the Scottish Government paid ­thousands to top lawyers to try to block MSPs from ­hearing key evidence.

Leaked emails showed a firm was hired using public cash and demanded investigating committee members give written guarantees they wouldn’t ask a senior official crucial questions.

No-go areas related to meetings held between the FM and ­Salmond at her home in 2018. Detail of the appointments form the basis of allegations Sturgeon broke the Ministerial Code of Conduct. They should have been recorded if they were to discuss Government business rather than party affairs.

When MSPs refused to sign up to RGM Solicitors’ demands, the witness – a senior official – failed to give ­evidence at all. It previously emerged ministers spent more than £50,000 to prepare civil servants to give evidence.

Sturgeon has also been accused of ­breaking the Code by misleading ­Holyrood over what she knew and when.

She initially told Holyrood she first heard of ­complaints against him when they met at her home on April 2, 2018.

After it emerged she discussed the allegations in her Holyrood office four days earlier, she has said she “forgot”.

Earlier this month, the Sunday Mail reported revelations by sources that Sturgeon received legal advice from Scotland’s most senior lawyer Roddy Dunlop QC her Government would lose to Salmond months before blowing £692,000 fighting his judicial review.

After his judicial review victory, ­Salmond was charged with 14 offences. He was cleared of all charges. The Scottish Government declined to comment.