The Liberal Democrat peer Chris Rennard has been told there will be no further investigation into sexual harassment allegations made against him, after an independent panel concluded it could not reopen the claim. This was reported by Qazaqyia.kz citing The Guardian.

The party leader, Ed Davey, said he was "disappointed and upset" by the conclusion, having suspended Rennard from the party after an investigation was reopened earlier this year amid claims a previous inquiry was flawed.

Rennard said the complaint should now be published in full and said it made clear the reopened investigation should never have happened.

The Lib Dems had asked three independent adjudicators, who are party members, to reassess Rennard's conduct after the party received advice that a 2013 investigation into the claims made by four women against the peer had been "flawed in several respects".

But it is understood that, after taking legal advice, the panel concluded that without new evidence, the case could not be reopened. Rennard is a former chief executive of the party who was awarded a life peerage in 1999.

Davey has said previously he does not believe Rennard, 66, should be a member of the party or the House of Lords but does not have the power to remove him.

Davey said in a statement: "People will share my disappointment and upset that the independent process has come to this conclusion but it is rightly independent. The women who made complaints were let down by a flawed investigation 13 years ago, which is why we've changed the system, and it is deeply frustrating that they are now let down again because the process has concluded that this cannot be reinvestigated. However, I do have complete confidence that the current complaints system would handle a new complaint of this nature in a wholly different and much more reliable way."

Rennard has been subject to a series of investigations by police and lawyers that concluded that the allegations against him could not be proved. He has said he apologises if he "inadvertently encroached" on anyone's "personal space".

The four claimants are former deputy party chair Alison Goldsworthy, the academic Alison Smith, Bridget Harris, a former adviser to Nick Clegg, and the former councillor Susan Gaszczak.

A review carried out by the senior lawyer Alistair Webster KC in 2013 concluded that there was a less than 50% chance of the case against Rennard being proved beyond a reasonable doubt. But in a statement summarising his findings, he said there was "broadly credible" evidence of "behaviour which violated the personal space and autonomy of the complainants".

In a statement, Rennard said all the allegations had been "thoroughly and professionally investigated and dismissed by both police and by independent inquiries over 17 months in 2013-14".

He said: "The large volume of evidence which led Alistair Webster KC to dismiss the complaints remains confidential to his inquiry and there is no basis for suggesting that a different process could have come to any other conclusion."

Rennard said those conclusions had been formally accepted by the party at the time. "The appeal by the unsuccessful complainants against Alistair Webster KC's decision was dismissed by the Appeals Panel on the basis that there were no grounds for it," he said. "The decisions of this Panel were described in the party constitution as being 'final and binding on all the parties' and the party's own lawyers confirmed that the decision was final in law."

"The decision of the complaints panel, which met on 11 October, and which I was informed of today, is very damning of the party. The legal advice which the complaint relied upon was never properly made known.

"The party has spent a lot of money on lawyers including to obtain further legal advice from a KC. This further advice, together with other submissions, resulted in the panel dismissing the complaint. This latest advice should also be made known to me as the party says that it has been shared."

Rennard criticised the party for taking nine months to dismiss the complaint, saying it had "been unfairly damaging to me and my wife, to the party of which we have both been members for over 50 years, and to the many good causes and good people that we support".

Rennard's solicitor Richard Cannon said the renewed complaint had been "legally flawed from the outset and should never have been brought".

Rennard has been approached for comment on the latest development that there will be no further investigation into the allegations.