The Liberal Democrats have expressed "regret" over the handling of strongly denied allegations of inappropriate behaviour towards women by a senior party figure.
Chief executive Tim Gordon said it appeared the party "did not fully live up to our political ideals" in dealing with complaints about predecessor Lord Rennard.
The peer - 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.
Channel 4 News reported on Thursday that two women had claimed Lord Rennard touched them inappropriately. 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 spokesperson for women and equality, Jo Swinson, about her claims, but claimed no action was taken.
A fresh report by the programme on Friday said more women had come forward with similar stories.
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 this evening, 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".