A former lord advocate has ruled herself out of leading the investigation into the First Minister’s actions during the Alex Salmond sexual misconduct probe after flagging up a potential conflict.

Dame Elish Angiolini is one of two senior legal figures who could front the probe, but she declined because she is in charge of a review of the wider police complaints system.

She told the Herald on Sunday she understood the referral would be considered by former prosecutions chief James Hamilton.

A spokesman for the Scottish Conservatives said: "This is a welcome decision from Dame Elish Angiolini, and one she should be commended for. It's vital the process isn't only impartial, but seen to be impartial."

Allies of Sturgeon and Salmond have been engaged in a briefing war over the SNP Government’s botched handling of sexual misconduct complaints into the former First Minister.

Two female civil servants complained about Salmond’s alleged behaviour in office, after which an internal probe was launched followed by a police referral.

But Salmond, who denies the allegations, won a judicial review against the investigation after claiming it was “unfair and unjust”.

The probe fell foul of the law after a civil servant who had prior contact with the complainants agreed to become the investigating officer.

Since his court victory, pro-Salmond figures have been blamed for a series of unfavourable briefings against permanent secretary Leslie Evans, the First Minister, as well as Sturgeon’s chief of staff Liz Lloyd.

The row has moved on from the misconduct investigation to Sturgeon’s contacts with her predecessor when it was ongoing.

She confirmed meeting Salmond three times, twice at her home, as well as speaking to him on two further occasions by telephone. She has denied any interference.

Parliamentary scrutiny prompted Sturgeon to refer herself to an independent panel of advisers who can judge whether she has breached the Ministerial Code.

The advisers are Angiolini and James Hamilton, who is the former Director of Prosecutions at the Irish Office of the Director of Public Prosecutions.

Angiolini was appointed Lord Advocate by former Labour First Minister Jack McConnell in 2006. As a senior law officer, she combined the roles of chief prosecutor and chief legal officer to the Government.

She continued in the post when Salmond became First Minister in 2007 and was Lord Advocate until 2011.

Figures obtained by this newspaper showed that Angiolini appeared at Cabinet, which was chaired by Salmond and included Sturgeon as Health Secretary, nearly 30 times.

On Friday, the Scottish Tories initially said there was a “risk” the public may believe her previous Government link could “deem her unsuitable for this particular task.”

However, the former Lord Advocate has revealed that days earlier she declined to consider taking the referral after feeling "conflicted" over a different matter. In June last year, the Justice Secretary announced Angiolini would front an independent review into all aspects of the system for police complaints handling, investigations and misconduct.

She said: “As you will know, I am carrying out a review of complaints against the police in Scotland. In light of that ongoing review I advised the Head of the Cabinet Division on Monday that I considered myself conflicted. I declined to consider the reference which I understand will be considered by Mr Hamilton. The story in the press that I will be heading up the investigation is wrong.”

The remit of the Angiolini review includes assessing and reporting on the effectiveness of the current law and practice, as well as making and recommendations to the Justice Secretary and the Lord Advocate for improvements to ensure the system is “fair, transparent, accountable and proportionate”.

A Scottish Government spokesperson said: “The Ministerial code adviser who will investigate this matter will be announced in due course.”