Using parliamentary privilege in the House of Commons, Conservative MP David Davis read out messages that he suggested showed a “concerted effort by senior members of the SNP to encourage complaints” against the former first minister.
According to Mr Davis, the messages disclosed by a whistleblower “demands serious investigation”, with one alleging the investigating officer in the case complained of interference by Ms Sturgeon’s chief of staff.
The message is alleged to have been sent by Judith Mackinnon to the Government’s communications director on February 6 2018, almost two months before the First Minister claims to have first known about the investigation of her predecessor.
Mr Davis said: “The investigating officer complained ‘Liz interference v bad’ – I assume that means very bad.
“If true, this suggests the chief of staff had knowledge of the Salmond case in February, not in April, as she has claimed on oath.
“The First Minister also tied herself to that April date in both parliamentary and legal statements.
“She was of course aware earlier than that: the question is, just how aware and how much earlier?”
Challenged about the claims during the Scottish Government’s coronavirus briefing on Wednesday, Ms Sturgeon insisted she has confidence in her chief of staff and she “strongly” denies the allegations.
Ms Sturgeon said: “Other than to say that I strongly refute [sic] the suggestions and insinuations of David Davis in the House of Commons last night, I am not going to have this Covid briefing sidetracked by the latest instalment of Alex Salmond’s conspiracy theory.
“I have given eight hours of evidence to the parliamentary committee looking into this.
“They are now able to assess all of the evidence they’ve taken, including, I’m sure, the evidence they have in relation to the suggestions and claims made by David Davis last night.
“They have a job of work to do, now, I’m going to allow them to do that job of work and, in the meantime I’m going to get on with my job.”
The Committee on the Scottish Government Handling of Harassment Complaints was set up after a successful judicial review by Mr Salmond resulted in the Scottish Government’s investigation being ruled unlawful and “tainted by apparent bias”, with a £512,250 payout being awarded to him for legal fees in 2019.
In the Commons on Tuesday evening, Mr Davies also accused the Scottish Government of obstructing the Holyrood inquiry into the saga, adding: “This was a Government that actively withheld important, relevant information.
“In one case a critically relevant email was actively removed from an information bundle that was going to the court and which had already been approved by government counsel. I don’t know who took that email out – I have it here.
“I don’t know who took it out, I don’t know who gave the instruction. But in my view the removal of that document would be a summary dismissal offence, and possibly a criminal offence. At the very least it would be in contempt of court.
“And yet over his three evidence sessions the Lord Advocate, the chief law officer of Scotland, did not see fit to mention this crucial incident to a parliamentary committee trying to get to the truth. It only came to light just 10 days ago when the government was forced to publish its legal advice.”
Asked about the apparent withdrawal of the document, Ms Sturgeon argued it was part of a “conspiracy theory”.
Earlier, a spokesman for Ms Sturgeon said: “As with Mr Salmond’s previous claims and cherry-picking of messages, the reality is very different to the picture being presented.
“Every message involving SNP staff has been seen by the committee previously. Their views have been widely reported as dismissive of them.”
A Scottish Government spokesman said: “The assertions made by David Davis are wrong – this document was not withheld, it was provided to the Court on 21 November 2018.
“The Scottish Government absolutely refutes the allegation that civil servants sought to obstruct or show contempt for the court process.”