MP Simon Danczuk denies rape allegation made against him
Rochdale MP Simon Danczuk says a historical rape allegation made against him is "malicious, untrue and upsetting".
Lancashire Police said it had received a report of a rape allegation dating back to 2006.
A spokesman said: "We are in the very early stages of an investigation and inquiries are ongoing."
Last week the MP was suspended by the Labour Party after he admitted sending lewd texts to a 17-year-old girl.
Responding to the rape allegation, Mr Danczuk said: "These claims are malicious, untrue and extremely upsetting.
"The police have not been in touch with me but I will co-operate fully with any inquiries and am confident my name will be promptly cleared."
He has faced sustained calls for him to resign following the separate matter of the text messages he admitted sending to teenager Sophena Houlihan.
Speaking to BBC Radio 5 live, his ex-wife Karen Danczuk said sending the messages showed "naivety on his part".
"I don't think it's a lack of judgement, it's naivety. And I think what he doesn't realise - and one thing I had to learn very quickly in these last 12 months - public life is not easy and these people aren't your friends.
"He's fallen for all of these messages that he thought were genuine."
"This happened on one night, one evening this happened. One night he had too much to drink," she added.
A small group of people staged a demonstration outside the MP's constituency office on Monday.
However, Mr Danczuk, who blamed a "drink problem" for the sexually explicit messages, told the BBC he had no intention of standing down.
He also admitted receiving £1,100 from a photographic agency that sells pictures of him to tabloid newspapers and magazines.
Speaking to Newsnight, Mr Danczuk defended the arrangement with FameFlyNet.
He said it was a properly declared payment for "media advice and [to] give ideas about what they might or might not do."
He added: "I don't make any apologies for it."