In a statement this evening, Mr Alexander said:
As I said yesterday, I did not know about these specific allegations until the Channel 4 broadcast.
When indirect and anonymous concerns about Chris Rennard's conduct came to the attention of Nick Clegg's office, in late 2008, we acted immediately.
As Nick's Chief of Staff, I put these concerns to Chris Rennard in strong terms and warned him that any such behaviour was wholly unacceptable.
Chris Rennard categorically denied that he had behaved inappropriately as he continues to do. Chris Rennard subsequently resigned as Chief Executive on health grounds.
As these concerns were received indirectly and anonymously, as those involved understandably wanted to maintain privacy, there was a limit to how we could take this matter forward following Chris Rennard's resignation.
The party has rightly set up inquiries into these matters and I will participate fully in those processes.
Nobody thinks Nick is the kind of guy who would defend a 'boy's club', but that does not necessarily mean he has handled the issue well.
One of the women who made allegations against Lord Rennard told ITV News that Lib Dem leader Nick Clegg shifted his position on the matter.
Questions for the Lib Dems mount, centred on what senior members knew about allegations surrounding former chief exec Lord Rennard and when.