Sky sources say that "several" women have called a Scotland Yard hotline over sexual harassment allegations relating to the former Lib Dem chief executive.
They include a former party activist who has told Sky News that she offered to make an official complaint that the peer had made inappropriate sexual advances towards her.
The claim by Alison Smith contradicts accounts from Lib Dem leader Nick Clegg and the party's senior leadership that no formal allegations were made about Lord Rennard.
Several women have come forward to accuse him of inappropriately touching and propositioning female party workers. Lord Rennard denies all allegations of wrongdoing.
Ms Smith told Sky News she first reported a complaint about the peer to Paul Burstow, then the chief whip, in April 2007. She is among those who have now called the police hotline to report their experiences.
"That wasn't listened to so I took the matter to various other people and really kept hitting brick walls," she said.
"At the time, I didn't have any ambitions for a political career, so I felt less prohibited coming forward and complaining.
"I said from the very first instance to Paul Burstow that I was willing to take (my complaint) all the way. I told him I was willing to put it in writing and to go to the police if he thought that was the right thing to do."
Ms Smith said the matter was dealt with informally in 2009.
Mr Clegg earlier conceded that his party made "very serious mistakes" in failing to deal properly with complaints of sexual harassment against the peer.
The Deputy Prime Minister admitted women in his party were "let down" when their allegations of sexual harassment against the peer were not listened to.
Lady Williams, the former Lib Dem leader in the House of Lords, stepped into the row saying that it had been "hopelessly exaggerated".
"Chris Rennard, in my view, is a very fine man, and I think the whole thing has been hopelessly exaggerated," she said.
"Let’s be frank, the bad stuff is basically what’s happened to Savile. It's abusing children, it's abusing very young innocent women, it's using the temptations of celebrity.
"And all that, I completely understand that this is terrible, simply terrible. I don’t think anything that’s been said about our chap is in the same category at all."
Lord Rennard issued a fresh denial of any wrongdoing this week and has said he is ready to "co-operate with any properly-constituted inquiry".
The statement said "that in 27 years of working for the Liberal Democrats he received no complaint or allegation about his behaviour".