Leading UK sporting bodies are warning that they are unable to share crucial child protection information.
New figures given to the BBC reveal that 124 allegations of sexual abuse in sport were made last year.
There are fears that under the current system those accused can move to another sport or part of the country.
The Independent Safeguarding Authority says it is limited in the information it can share with sporting organisations.
Figures gathered by Brunel University show that of the 652 child protection issue cases examined by national governing bodies in 2011, almost a fifth involved allegations of sexual abuse.
Some led to criminal prosecutions but 98 were referred back to the sport by the police or children's services.
"They are the cases in which the sports are left in a kind of limbo about really knowing what to do," says Dr Daniel Rhind who carried out the research.
"Maybe there wasn't enough evidence or no chance of prosecution.
"Obviously there are the extreme cases of sexual abuse where it's clear-cut and it will go to the police, but slightly further down the line there are a lot more grey areas."
File on 4 can reveal a disciplinary hearing earlier this year found one of British judo's leading coaches was involved in abusing five athletes over 33 years. Until now the details of the hearing have not been made public.
Alan Roberts, who trained champions and Olympians, helped build the Dartford Judo Club, which is one of the leading sports facilities in the country.