Kick It Out chairman Herman Ouseley believes recent allegations of bullying and racism within football are the "tip of the iceberg".
Chelsea’s former youth coach Graham Rix and ex-chief scout Gwyn Williams on Friday denied "all and any allegations of racial or other abuse" after they were the subject of shocking allegations in the Guardian newspaper.
Also on Friday, Bournemouth defender Tyrone Mings revealed he has received thousands of racist posts on social media, the abuse hitting new heights after he received a retrospective five-match suspension for stamping on Manchester United striker Zlatan Ibrahimovic in March last year.
Newcastle on Tuesday announced under-23s coach Peter Beardsley was on a "period of leave" as an investigation into allegations of bullying and racism continued. Beardsley denies the allegations.
"The fact is that a lot of people who make complaints still feel let down," Ouseley said, quoted in the Daily Mirror.
"It is a tip of the iceberg. It just tells you what a lot of people have gone through over the years which we know they have gone through - across the entirety of football.
"It is very difficult to comment on individual cases once a process is in place. But, in general, there is a problem with the way that inquiries are conducted, support given to complainants."
Liverpool’s 17-year-old forward Rhian Brewster recently told the Guardian of a host of incidents of racist abuse he has suffered in the game.
Ouseley, the former chief executive of the Commission for Racial Equality, said his organisation still receives reports of cases in which players were too scared to speak out.
"There is a fear factor with professional football which has existed in the dressing room and on the training ground," he added.
"Certainly anyone with aspirations as a black person to play professional football has kept their heads down and tried to avoid taking on the established status quo of challenging the coach, the trainer or the football manager.
"They have not gone outside of that arena to try and get redress because where they have and where they know of anyone challenging, they have had their heads chopped off. That has been the death of their careers."