A Lancashire councillor has made a complaint to police that he was physically abused by the late Rochdale MP Sir Cyril Smith in 1964.
Rossendale councillor Alan Neal said that at the age of 11 he was hit by the politician at a hostel for boys.
His complaint came on the day a blue plaque honouring Sir Cyril was taken down from Rochdale Town Hall.
A Lancashire Police spokesman confirmed the force was investigating Mr Neal's complaint.
Mr Neal said he had not made the accusation against the late MP before because it was "something that you don't speak about".
"I'm speaking now because someone has taken a right decision to raise this issue with the authorities," he said.
"Hopefully, those authorities are now going to pursue this matter."
Mr Neal added that he told police about the incident in 1968 when he left the school but on raising it "everyone made the same comment that the person in question was a very important, powerful man".
He said he could vouch for Sir Cyril being a powerful man "because he picked me up off the floor and that has probably had a lasting impact on my life".
In the House of Commons on Tuesday, Rochdale MP Simon Danczuk called for a "full investigation" into allegations that Sir Cyril had indecently assaulted boys in care at the same home.
Sir Cyril's brother said the late MP had denied the allegations.
Mr Neal's comments come after Rochdale Council removed a blue plaque to Sir Cyril, as a "neutral act to prevent vandalism".
The plaque was unveiled last year by former Liberal Democrat leader Sir Menzies Campbell.
Councillor Colin Lambert (Lab), the leader of Rochdale Council, said: "This is not a judgement on either Sir Cyril Smith or anyone else.
"We discussed this at a meeting last night and had decided to leave it up but we received information that it could be damaged overnight and took it down because this would be a danger to the town hall."
On Wednesday Barry Fitton, one of three alleged victims from a Rochdale care home, claimed that the former MP smacked him and stroked his buttocks.
Mr Danczuk (Lab) told the Commons that claims against the late MP had "circulated for years".
Lancashire Police said an investigation was "believed" to have taken place in the 1960s, but "no records are held".
Mr Danczuk said police "should consider reopening the case".
Manchester-based solicitors Pannone have confirmed they are currently dealing with an allegation of abuse against Sir Cyril, who died in 2010.