Police have identified "a number of suspects" as part of an investigation into alleged sexual abuse at a school linked to the late MP Cyril Smith.
Greater Manchester Police (GMP) added more alleged victims had come forward over claims about Knowl View School in Rochdale from the 1970s.
The allegations related to at least 11 potential suspects.
Rochdale Council said it was launching an inquiry into a possible abuse cover-up at the residential school for boys.
It is understood nine people have contacted police to say they were abused from the 1970s onwards by adults at the school, which closed in 1992.
No-one has been arrested.
GMP Chief Constable Sir Peter Fahy said: "I would like to appeal for victims of abuse to come forward.
"We recognise this is a hugely difficult decision for the people involved, particularly when they involve events many years ago."
He said officers were also trying to trace a "significant" number of people in relation to the investigation.
In 2012, the force investigated claims Smith abused young boys in the 1960s while in his role as secretary of the Rochdale Hostel for Boys Association.
He had been accused of abusing eight youngsters at Cambridge Hostel in the town by spanking and touching them.
Three separate files were passed to the director of public prosecutions and the Crown Prosecution Service, although on each occasion no prosecution was pursued.
Rochdale Council, which launched its own a formal investigation into Knowl View school in January, said it was now undertaking an independent review.
Smith's family has said he always denied such accusations and said on Monday they welcomed the review.
GMP has also said it is also carrying out an investigation into whether there is evidence of a criminal cover-up over the abuse allegations.
The claims were published in a book by Rochdale's Labour MP Simon Danczuk called Smile for the Camera: The Double Life of Cyril Smith.
Smith was a governor and then later became the chairman of governors at Knowl View School.
Police, spies and politicians covered up the child abuse carried out by Smith, according to Mr Danczuk's book.
The former Rochdale Liberal MP was left free to abuse children as young as eight despite 144 complaints by victims, the author claimed.
Sir Peter said: "We are carrying out a review into those allegations and other matters of public debate around that book to see whether that justifies a criminal investigation into allegations of a cover-up."
Rochdale Council said its review would cover a number of areas including whether abuse was "tolerated, facilitated or promoted" by the council or there was a "culture" at the council, which "inhibited the proper investigation, exposure and prevention of such abuse".
Council leader Colin Lambert said: "It is clear that to ensure there is public confidence in the thoroughness of the review we must widen its scope to include a review of all information available to the council."
He said any evidence they found which was "relevant to allegations of criminal activity" would be passed on to the police.
The inquiry will review the council's conduct between 1961 and 1995, when sexual or physical abuse is alleged to have taken place.
The findings will be reported back to the council by the end of July.
Following the announcement, Smith's family issued a statement which said: "The family welcome the review and now wish to know finally what is true and what isn't.
"We will co-operate with any review or investigation the authorities undertake.
"We repeat Sir Cyril always maintained his innocence about the inquiries made in the 1960s and any subsequent investigations by the GMP or Lancashire Police force.
"Nobody in the family has any knowledge whatsoever of any of the recent claims made in the press and/or Simon Danczuk's Book."
Smith was MP from 1972 to 1992. He died in 2010 aged 82.