The chief executive of the Professional Footballers’ Association, Gordon Taylor, has revealed the number of players making allegations of child sexual abuse in football is now more than 20, and he has alleged that Leeds United and Blackpool can be added to Crewe Alexandra, Manchester City, Newcastle United and Stoke City on the list of clubs connected to the claims.

Earlier, the FA announced an internal review into what it and the clubs involved knew at the time of the alleged offences, which may become a full-blown inquiry later down the line.

Taylor, speaking to Radio Five Live’s Sportsweek, said up to seven clubs were connected to the allegations of child sexual abuse and said he expected the issue to widen in scale.

“From that time, of those who became apprentices and senior players, over 20 players have come forward,” said Taylor.

Asked to name the clubs that had been connected to allegations thus far, Taylor said: “We’d start at Crewe, go to Man City, Stoke, Blackpool, Newcastle, Leeds … I’m expecting there will be more. I think we have six or seven clubs.

“I can’t believe it’s just going to be in the north-west and north-east. We need to be mindful this could be throughout the country in the same way it’s been in other professions where children are there – in the church, in schools.”

Press Association Sport has contacted Leeds and Blackpool, clubs who had not previously been linked with the current raft of allegations, for comment.

Taylor suggested that some of the mental health issues his organisation has been attempting to counter in recent times could be tied to abuse but also spoke of his confidence that youth players were better protected now than in the past.

“We’ve had issues of depression and, of course, issues that caused suicides … some of what might be coming out might help explain that as well,” he said. “I wouldn’t preclude the fact it could happen [now] because you can’t have enough vigilance when paedophiles are so determined.

“But we have the PFA safety net, an online platform available to parents and youngsters informing them of danger situations. There’s a lot more knowledge available about what needs to be done and checks on staff at clubs.”

Barry Bennell, the convicted paedophile and former youth coach who has been named by players including Andy Woodward, Steve Walters, David White and Ian Ackley, worked with Crewe, Manchester City, Stoke and several junior clubs in the north-west.

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 player that he was abused in the club’s youth system after his story was told in the Guardian. Newcastle said they would co-operate with authorities “if or when the club receives further information”.

Crewe Alexandra football club has said it will launch an independent investigation into how it has dealt with child sex abuse allegations concerning a former youth team coach.

Stoke said on Thursday night they had not been approached about any specific case of abuse but were ready to launch an investigation into any allegation raised. Manchester City said in a statement: “The club is aware of allegations that Barry Bennell had an association with Manchester City football club in the 1980s. As a result the club is currently undertaking a thorough investigation of any past links he might have had with the organisation.”