North Norfolk MP and government minister Norman Lamb has told how a woman contacted him to allege that a Liberal Democrat peer had behaved inappropriately towards her.

The woman, whom Mr Lamb said he still knows, is one of several who has now made allegations of sexual harassment, including improper touching, against former Lib Dem chief executive Lord Rennard.

Furore around the allegations escalated after deputy prime minister and Lib Dem leader Nick Clegg admitted knowing about some concerns five years ago.

The admission led to suggestions a cover-up had taken place, given the allegations were only now emerging, though Mr Clegg denied that.

Instead he repeated his claim yesterday that only 'general concerns' were raised with him in 2008, which did not include 'specific allegations'.

After that happened, his chief of staff at the time Danny Alexander – now chief secretary to the treasury – confronted Lord Rennard, warning him that any such behaviour was 'wholly unacceptable'. The peer denied any improper behaviour.

Mr Lamb told the Eastern Daily Press yesterday that when the woman brought her allegations to him he advised her to take the complaint to Lib Dem MP Jo Swinson, who is now the party's minister for women.

He said: 'A woman who I know and who I maintain good relations with talked to me about [her allegations]. I encouraged her to take it to Jo.

'I knew Jo was dealing with a number of women [in relation to allegations against Lord Rennard] and I know that Jo was taking it seriously.

'She did speak to Jo, who has now made a statement saying that she referred the issue on. That resulted in action being taken in the form of [Lord Rennard] being talked to by Danny Alexander.'

He went on: 'Jo and I both felt the same, that action had to be taken.'

Mr Lamb said he was not aware whether specific allegations of the woman's case had been relayed to Mr Clegg, adding that she had wished to remain anonymous.

Party president Tim Farron acknowledged yesterday that the Lib Dems had 'screwed this up' and failed in its duty of care to the women involved.

The party is now setting up an independent whistle-blowing service so, if others wish to make allegations, they can do so. Meanwhile, they are investigating both the allegations and the way they were dealth with.

Lord Rennard denied all allegations last Friday saying he was 'disappointed and angry' that accusations from several years ago had been made public in what he called a bid to damage his reputation.

He added: 'Let me reiterate that in 27 years working for the Liberal Democrat party, not a single personal complaint was ever made against me to my knowledge.'