It comes after it emerged that Bennell, a former Crewe Alexandra coach, was treated by paramedics and taken to hospital on Friday night after being found unconscious, in what police called a "fear for welfare" incident.

GMP urged more victims to come forward and said complaints would be treated seriously.

Assistant Chief Constable Debbie Ford said: "Following recent media coverage, Greater Manchester Police has received a number of calls from people reporting historic sexual abuse whilst they were in the youth football system.

"We have now launched an investigation and our specially trained officers are supporting those who have come forward so far.

"We are co-ordinating our investigation with forces nationally and with Operation Hydrant, the national co-ordination hub for historic child abuse investigations concerning persons of public prominence.

"I would encourage anyone who was a victim of sexual or physical abuse to come forward and speak to us as soon as possible.

"I completely understand that for many people, making disclosures about such traumatic events can be difficult, but we will offer advice and support throughout."

The Football Association (FA) is facing mounting pressure to expand the scope of an inquiry into abuse.

Damian Collins MP, chairman of the Commons Culture, Media and Sport Committee, accused the FA of being slow in responding to the growing scandal.

English football's governing body appointed senior lawyer Kate Gallafent QC to assist with its review into historical child sex abuse allegations starting in the 1970s.