Nicola Sturgeon has rejected the “absurd” allegation the Scottish government plotted to destroy Alex Salmond’s reputation but admitted it made serious mistakes in its investigation into complaints against him. The first minister said her government made a “dreadful, catastrophic mistake” during its inquiry into two sexual harassment complaints against Salmond by appointing an official who had previously spoken to the complainers as its investigation officer. That decision led to the government losing a judicial review taken by Salmond, costing taxpayers more than £600,000. “Two women were failed and taxpayers’ money was lost,” she said. “I deeply regret that.” Closely questioned by MSPs during a marathon eight-hour evidence session at the Scottish parliament, Sturgeon insisted her former mentor was wrong to accuse her, the Scottish National party or her officials of a vendetta or conspiracy against him. “I must rebut the absurd suggestion that anyone acted with malice or as part of a plot against Alex Salmond,” she said in her opening statement to nine MSPs investigating the government’s botched inquiry into the harassment allegations against Salmond, which he had denied. She later went further: “Alex Salmond has been for most of my political life, since I was 20, 21 years of age, my closest colleague. He was someone I looked up to, someone I revered. I would never have wanted to ‘get’ Alex Salmond.” Sturgeon came under pressure from MSPs to explain why there had been repeated delays in the release of the government’s legal advice, and key internal documents, as she offered new explanations about why she had met Salmond while the harassment inquiry was under way. Jackie Baillie, of Labour, alleged Sturgeon and Salmond had breached the confidentiality of complainers when he discussed their allegations against him in a meeting at her home on 2 April 2018, yet Sturgeon waited until early July before telling Leslie Evans, the permanent secretary, they had met. Sturgeon acknowledged she discussed Salmond’s criticisms of the inquiry with him five times partly because she felt loyalty towards him, but delayed telling Evans because she feared that would be seen as her interfering in the process. Labour and Conservative MSPs accused Sturgeon’s deputy first minister, John Swinney, of breaking the government’s promises to publish all its legal advice, despite his last-minute decision to release previously secret legal papers late on Tuesday afternoon. Several weeks of legal meetings were missing from the records Swinney released; Sturgeon promised more papers would be supplied. Those papers contained the explosive revelation that Roddy Dunlop QC, one of Scotland’s leading lawyers, who was the government’s external counsel, had been furious that government officials failed to disclose critical evidence about the prior contact of the investigating officer with the two complainants. Sturgeon told the committee she only learned of this apparent conflict of interest and its legal significance in November 2018. In a parallel development, the Tories said they were reconsidering their votes of no confidence against Swinney and Sturgeon, due to be heard on Thursday, after Swinney offered to release more legal information. The party said the motions were still live, but indicated they might be withdrawn. Sturgeon was pressed on whether she had investigated allegations that a senior government official had leaked the name of a complainer to Geoff Aberdein, Salmond’s former chief of staff, before Sturgeon met Aberdein in her office at Holyrood in late March 2018. Aberdein’s account was supported by Salmond’s lawyer Duncan Hamilton and his former spokesman Kevin Pringle, who told the committee on Tuesday Aberdein had made that claim in a conference call with him soon after he met that official. The Tory MSP Murdo Fraser said that was “an incredibly serious issue” and potentially unlawful. Sturgeon said Aberdein’s account had been denied by the official concerned but she said the allegation was included in an investigation by James Hamilton, Ireland’s former director of public prosecutions, into whether Sturgeon had broken the ministerial code. “That was not the way, as I understand it, that happened, in the way that is being set out,” she said. During a series of tense exchanges, Sturgeon said she had no idea who leaked news that the internal inquiry had upheld the complaints against Salmond to the Record newspaper in August 2018, despite his allegations a government figure must be to blame. “There was no part of me that wanted for this proactively to get into the public domain,” she said. The idea she would ever need to discuss this publicly made her feel “physically sick”. She also admitted that before she met Salmond at her home in April 2018, she “had a lingering fear, suspicion, concern” that allegations about his conduct might emerge. She knew Sky News had contacted the government in early November 2017 about alleged incidents involving Salmond at Edinburgh airport a decade earlier – claims Salmond denied – and had discussed them with him that month. Answering Salmond’s charges that she offered to intervene on his behalf in the government inquiry, Sturgeon said Salmond might have misunderstood what she said to him. Her written evidence said she had made clear to him she would not intervene, but Duncan Hamilton, who was present when Sturgeon met Salmond in her house on 2 April, told the committee in written evidence on Tuesday that he had heard her offer to do so “if it comes to it”. Sturgeon said Salmond may have misunderstood. “I believe I made it clear I wouldn’t intervene. [I] was perhaps trying to let a longstanding friend and colleague down gently, and maybe I did it too gently, and maybe he left with an impression I didn’t mean to give him.” The first minister said once Salmond had set out the allegations he was facing “my head was spinning. I was experiencing a maelstrom of emotions.” Sturgeon said the government had to investigate the allegations against Salmond, regardless of how powerful or famous he might be. She said many people, including her, had been let down by her former friend and mentor but he had not yet apologised. “When I saw him lashing out on Friday, I don’t know whether he ever reflects on the fact that many of us feel let down by him,” she said. “That is a matter of deep personal regret.”