The Liberal Democrats deny Nick Clegg knew about a series of complaints against the party's former chief executive Lord Rennard broadcast by Channel 4 News.
One of them, Alison Smith, a Lib Dem activist who is now a lecturer at Oxford University, said she had spoken to both the then Lib Dem Chief Whip Paul Burstow and the party's Spokeswoman for Women and Equality, Jo Swinson, about her claims, but said no decisive action was taken.
A second report on Friday said more women had come forward with similar stories.
The Mail on Sunday has published a Facebook discussion of claims from January 2009 in which one party worker wrote: "I just don't know how nick can know and not do anything."
Aides to the deputy prime minister insist he only learned of a series of complaints against Lord Rennard when Channel 4 News uncovered details this week.
The development came as current Lib Dem Chief Executive Tim Gordon admitted it appeared the party "did not fully live up to our political ideals" in dealing with complaints about the peer.
Lord Rennard - a key party strategist and adviser to a succession of Lib Dem leaders before standing down due to ill health in 2009 - has said he is "deeply shocked" by the allegations, which he "strongly disputes" and regards as a "total distortion" of his character.
The Lib Dems have launched an internal investigation into the "specific allegations" against Lord Rennard under the party's disciplinary procedures.
Party President Tim Farron is also conducting a review into the way the party dealt with such allegations.
Posting on the Lib Dem Voice website, Mr Gordon said many members would have seen media reports about the allegations and suggestions that the party failed to deal with them adequately.
"It appears that we did not fully live up to our political ideals, and I regret that," he wrote.
"I want to assure you that the party, and I as chief executive, are taking these questions very seriously - both as regards the specific allegations that were made, but also about the party's procedures for handling complaints of this sort."
He said a five-strong panel of party figures - including at least three women - would be assembled to carry out a "thorough and in-depth" probe into the allegations against Lord Rennard.
At the same time Mr Farron's review will look into how "allegations made in the past have been handled".
'Distortion of character'
Responding to the initial Channel 4 News allegations, a spokesman for Lord Rennard said: "He regards the report as a total distortion of his character.
"Not a single complaint of misconduct was made against him to his knowledge during the 27 years he worked for the Liberal Democrat party. Despite the claim made by one woman in the report, Lord Rennard continued working closely with her for ten years after the alleged event described.
"Until this matter is resolved he will withdraw from the Federal Policy Committee on which he serves and temporarily stand aside from the Liberal Democrat group in the House of Lords to seek to avoid any embarrassment to the party.
"He will remain a member of the Liberal Democrats and will continue to devote himself to good causes through his work in the House of Lords and elsewhere."
After the follow-up report on Friday Lord Rennard said in a statement: "I absolutely deny any suggestion of improper touching, nor did I invite a woman to join me in my room.
"I note that these alleged instances supposedly took place in public bars with other people present.
"I am disappointed and angry that anonymous accusations from several years ago are once again being made public in this manner in a clear attempt to damage my reputation.
"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."
22 February 2013
22 February 2013
21 February 2013