NICOLA Sturgeon is under growing pressure to suspend her friend and political inspiration Alex Salmond “with immediate effect” after police confirmed they are investigating sexual misconduct allegations against him.

Mr Salmond repeatedly denied criminal behaviour and insisted he has never sexually harassed anyone as he battled to save his reputation following explosive claims dating back to his time as First Minister.

It came as it emerged Ms Sturgeon refused to intervene in the Scottish Government’s internal investigation when Mr Salmond told her about the allegations earlier this year.

She said the claims were “extremely difficult” to come to terms with but could not be ignored or swept under the carpet.

An internal Government probe was launched in January after two staff members complained of sexual misconduct by Mr Salmond at Bute House in December 2013, when he was First Minister.

In an extraordinary day for Scottish politics, Mr Salmond revealed he met Ms Sturgeon three times after being told of the claims, during which he raised concerns about the “fundamentally flawed” investigation into his behaviour.

Ms Sturgeon said she had “made very clear” she would not intervene.

The former First Minister is now taking the Scottish Government to court over its handling of the complaints process, and has demanded an inquiry into how details were leaked to a newspaper.

Scottish Labour’s shadow equalities secretary Monica Lennon said: “Given the serious nature of these allegations, it would be appropriate that the SNP suspends Alex Salmond's membership of the party with immediate effect.”

In a statement released on Thursday night, Mr Salmond accused the Scottish Government’s Permanent Secretary, Leslie Evans, of carrying out a “grossly unfair” investigation into the claims, branding some of them “patently ridiculous”.

But Ms Evans said his statement contained “significant inaccuracies”. She also revealed Mr Salmond attempted to gag her from publicising the complaints by issuing legal proceedings.

Mr Salmond is now pursuing a judicial review of her probe, and insisted that if he wins “there will be serious questions to answer at the top of government”.

During a lengthy press conference, he refused to detail the nature of the allegations against him, whether he was anticipating more claims or whether complaints had previously been made about his behaviour as First Minister.

He also refused to say whether he had suggested to Ms Sturgeon that the Government’s investigation be dropped, instead answering: “Private conversations as far as I’m concerned are private conversations.

“What I would say is the very legitimate concerns, reservations, arguments about the nature of this, I have made to everybody at every possible opportunity.”

Mr Salmond did not rule out suing Ms Evans or the Scottish Government for defamation after the current legal proceedings have finished.

He said he is “no saint” and has made “many mistakes in my life – political and personal”, but denied sexual harassment or criminality.

The former politician said his family and friends – including his wife of almost four decades, Moira – had been “incredibly supportive”.

He insisted it was made “explicit” to him when the Scottish Government launched its probe that it would be “totally confidential”. But this was breached, he argued, when Ms Evans told him on Wednesday afternoon that she was making the claims public.

He said: “It’s only through a fair process that you can get a fair result. In the procedure of the Scottish Government, I had no access to evidence, witness statements. I was denied the right to speak to any serving civil servant.”

Asked if he thought he would be suspended from the SNP, Mr Salmond said: “I would advise everybody to suspend judgment until the court can make a judgment.”

He said he did his “absolute best” to cooperate with the civil service investigation, but had only seen a summary of the complaints against him and was not told the identity of the alleged victims.

But he insisted he was not seeking any sympathy. He said: “If I lose at the Court of Session then as I said, I’ll have to answer the complaints openly and publicly and I’ll do that as far as I’m able, with confidentiality and all that.

“But I don’t expect to lose. I expect to win. And that will have serious implications for the top administrators in the Scottish Government, but it might have beneficial consequences for a better process in the future.”

Ms Sturgeon said Mr Salmond’s membership of the SNP would be “considered in the fullness of time” as more information became available.

A police spokesman said: "We are carrying out an assessment of information which we have received and enquiries are at an early stage.”