The SNP is facing fresh claims that senior party figures conspired against its former leader Alex Salmond.

One of its own Westminster MPs has told Sky News that high-ranking members of the party shared dozens of messages about the former first minister in a social media group chat, calling themselves the “Vietnam” group.

In text exchanges before last year’s criminal trial of Mr Salmond, which resulted in his acquittal, it’s claimed they discussed the reluctance of an alleged victim to give evidence and efforts they could take to give her encouragement.

The new claims are made by Kenny MacAskill, the SNP MP for East Lothian and Scotland‘s former justice secretary.

He has told Sky News that content of the digital communications has long been a subject of open discussion within SNP circles, and he has backed calls for Scotland’s Crown Office to release the text messages as written proof.

Of the unpublished messages, Mr MacAskill told Sky News: “There has been long-standing talk in SNP circles about WhatsApp and text messages and I’ve been in correspondence with the Crown (office) about it. There’s a WhatsApp group that was called the ‘Vietnam’ group that included SNP staffers and even members of government.”

Referring to the trial of Alex Salmond, who was cleared of the sexual assault charges, Mr MacAskill said: “There is one text message between two senior members of staff seeking to put pressure on one of the alleged victims who was expressing reluctance about proceeding and they discussed ways of getting her ‘back in the game’.

Sky News has been told that those included in the “Vietnam” group are close colleagues of First Minister Nicola Sturgeon, but that she wasn’t a member.

A group chat is a facility on social media that allows a number of individuals to create a digital discussion forum.

The “Vietnam” moniker stemmed from Operation Diem, the name of the police investigation into Mr Salmond.

Mr MacAskill said: “It apparently came about because the police operation against Alex Salmond was termed Diem, which is obviously the Latin for ‘day’. Someone seems to have misunderstood Diem as a reference to a former president of Vietnam.”

Records of digital communications are now being sought by the Scottish parliamentary inquiry looking into the government’s handling of harassment complaints against Mr Salmond.

Its investigating committee has demanded that the Crown Office release records of text messages, among other documents, and has taken the unprecedented step of using legal powers under the Scotland Act to do so.

Committee members have asked for text or WhatsApp communications between Susan Ruddick – the chief operating officer of the Scottish National Party – and members of the Scottish government, its civil servants and special advisers from August 2018 to January 2019.

Kenny MacAskill has previously obtained two messages sent by Peter Murrell, the SNP’s chief executive and husband of Ms Sturgeon, in which Mr Murrell allegedly encouraged a prosecution of Mr Salmond. He admitted sending the communications before a parliamentary inquiry.

Both of those were sent to Ms Ruddick on the day after Mr Salmond’s first criminal court appearance in January 2019.

The first one read: “Totally agree folk should be asking the police questions… report now with the PF on charges which leaves police twiddling their thumbs. So good time to be pressurising them. Would be good to know Met looking at events in London.”

The second message, which appears to refer to the Crown Prosecution Service (CPS) in London, read: “TBH the more fronts he is having to firefight on the better for all complainers. So CPS action would be a good thing.”

The Metropolitan Police in London received one complaint in connection with the Alex Salmond investigation in January 2019 but dropped its enquiries after contacting the complainant as part of a case review.

Mr Murrell addressed the communications in a written submission to the harassment inquiry, stating: “The messages have been presented in a way that suggests a meaning that they do not in reality have.”

“My intention was to advise that their questions should be addressed to the Police and not the SNP.”

In his oral evidence to the inquiry, Mr Murrell was asked if there were any more text messages to any other party official on the same subject. Under oath, he replied: “No. Not that I’m aware of.”

Ms Sturgeon was asked on the BBC’s Andrew Marr programme if it was true there were no other text messages of “that nature”.

Ms Sturgeon replied: “There are no messages that are relevant to this committee.”

A spokesperson for the Crown Office told Sky News “COPFS has received correspondence from the committee requesting material and will respond in early course,” adding that it “must consider whether producing documents sought would be contrary to the public interest”.

Sky News has contacted the SNP and its chief executive, Mr Murrell, to ask for comment.