Former civil servant Lorraine Kay is believed to have written to MSPs stating that Geoff Aberdein, Mr Salmond's former chief of staff, told her the name of a complainer was told to him by a senior government official in early March 2018 and he then shared that name with her.
Her account, which has been revealed by The Guardian, follows similar statements published by the committee last week from Kevin Pringle, Mr Salmond’s former spokesperson, and Duncan Hamilton, an advocate who is also one of Mr Salmond’s lawyers.
Both men said they took part in a conference call with Mr Aberdein after he had met with the government official, and Ms Kay says he spoke to her on the same day.
Nicola Sturgeon has disputed Mr Aberdein’s account of the meeting with the government official. When she appeared at the committee, giving evidence under oath, Ms Sturgeon told MSPs his claims had been denied by the staff member concerned.
“The account that I have been given has given me assurance that what is alleged to have happened at that meeting did not happen in the way that has been described,” she said.
However, neither Mr Aberdein nor the unnamed official has testified to the committee for legal reasons, meaning their competing accounts have not been tested under oath.
Ms Kay, who worked in Mr Salmond’s private office for five years, has written to the Holyrood committee and to James Hamilton QC, who is investigating the First Minister for allegedly breaching the ministerial code.
She is believed to be the unnamed third witness who Mr Salmond referred to when he testified late last month, telling MSPs she was the first person Mr Aberdein spoke to after meeting the senior government official.
Ms Kay has said Mr Aberdein was “shocked” to be told by that official that Mr Salmond was under investigation and that he was also given the name of the complainer.
Her statement is expected to be published by the committee.
The Scottish Conservatives said the new claim raised “challenging questions” for Ms Sturgeon, who has repeatedly denied Mr Salmond’s allegations that she, her government and party conspired against him.
A Scottish Government spokesperson said: “The First Minister has made the position on this clear in her evidence to the committee last week and looks forward to the findings of the report from the independent adviser on the ministerial code.”
Earlier it was revealed by the Scottish Government that some records of meetings between Nicola Sturgeon, Permanent Secretary Leslie Evans and the Scottish Government’s legal counsel about the investigation into Alex Salmond cannot be found.
Depute First Minister John Swinney told the Holyrood committee he is unable to provide details that the committee had asked for.
Mr Swinney, who is facing a vote of no confidence on Wednesday after refusing Parliament’s demands to release legal advice for almost four months, had said the government did not record minutes of meetings with its external counsel about the former first minister’s ultimately successful legal challenge.