The scandal surrounding allegations of historical child sex abuse in football could spread to other sports, a senior police officer has warned.
A "significant" number of other alleged victims of abuse are likely to come forward and further sporting governing bodies may report similar problems, Chief Constable Simon Bailey, the National Police Chiefs' Council (NPCC) lead for child protection, said.
Four police forces are now investigating allegations of historical child sex abuse in football.
The national inquiry into child sexual abuse said it was "watching events closely" and opened the door to examining allegations in the growing scandal as England captain Wayne Rooney urged anyone who may have been assaulted to seek help.
A string of former footballers have come forward since Andy Woodward became the first to speak out last week about abuse he suffered at the hands of convicted child abuser Barry Bennell, a former Crewe Alexandra coach.
Bailey told BBC Radio 4´s Today programme: "I think it's probably a little bit too early to speculate but I suspect that in the next few days and weeks that we will see a significant increase in the numbers that are currently reporting allegations of abuse to us."
The Norfolk Chief Constable added: "We, as a country, are now having to deal with the legacy of non-recent sexual abuse and the thousands of allegations that we are now seeing across the country.
"We are receiving reports of abuse in all sorts of different institutions. I am not in the least bit surprised that we are now seeing the lid lifted on exploitation within the world of football and I suspect there will be other sporting governing bodies - again in the next few days and weeks - who will come forward and who will identify the fact that they have similar problems.
"I just think that we have more and more victims, thankfully, who are having the confidence to come forward knowing the police service's response and society's response to their abuse is now very different."
The Metropolitan Police, Hampshire Police and Cheshire police have said they are investigating allegations of abuse in the football community.
Northumbria Police said it was investigating an allegation by an unnamed former Newcastle United player that he was abused in the club's youth system.
The Guardian said an unnamed former Newcastle United player had contacted police to make allegations against George Ormond, a coach in the North East who was jailed for six years in 2002 for carrying out numerous assaults across a 24-year period.
Newcastle United FC said they would co-operate with authorities "if or when the club receives further information".
Some of the claims have come from the NSPCC which this week set up a dedicated hotline - on 0800 023 2642 - for football-related cases.
The Premier League said it is "very concerned" by the allegations.
A former Crewe board member said the club were told Bennell had sexually abused one of its junior footballers.
Hamilton Smith, who was on the board between 1986 and 1990, told the Guardian he called for a meeting after being told a boy had been abused.
Bennell was allowed to stay on but orders were issued that he should not be left alone with boys, Smith said.
He added: "This was discussed at the club's top level and, as much as I tried to resolve this, regrettably I couldn't. I dread to think how many victims there are, and my heart goes out to them."
According to The Daily Telegraph, leading football clubs made secret payments to buy the silence of young players sexually abused by coaches.
Former Manchester City youth team player Jason Dunford claimed on Friday the scandal was bigger than the Jimmy Savile revelations.
Chris Unsworth, 44, a former Crewe youngster who has also made allegations against Bennell, claimed it was "swept under the carpet".
Ex-England and Manchester City players David White and Paul Stewart and former Crewe player Steve Walters have also spoken out about being sexually abused by football coaches as children.
Bennell, who worked for Crewe, Manchester City, Stoke and junior teams in north-west England and the Midlands, abused young boys from the 1970s onwards.
He was jailed for four years for raping a British boy on a 1994 football tour of Florida, and given a nine-year sentence for 23 offences against six boys in England in 1998.
He was jailed for a third time in 2015 after admitting abusing a boy at a 1980 football camp in Macclesfield.
Crewe said it would conduct an internal investigation and Manchester City is also reviewing Bennell's links with the club.
Operation Hydrant, which oversees the investigation of allegations of historical child sex abuse within institutions or by people of public prominence, is trying to pinpoint the scale of the alleged abuse.
It has been in touch with all forces in England and Wales asking them to forward details of the allegations they have received following the recent publicity.