(CNN) Investigators who looked into suspicious betting patterns on professional tennis matches feel strong evidence they found was ignored, the BBC and BuzzFeed reported.
After a nine-month inquiry that began in 2007, the investigators turned over their report to officials from the Association of Tennis Professionals.
One of the investigators, Mark Phillips, told the BBC: "The evidence was very strong, as strong as we had seen really. It was as conclusive as you can get."
About 28 players were connected with the suspected match fixing, but the focus was on a group of about 10 competitors.
Phillips said he and the other two investigators continued to alert the ATP's new Tennis Integrity Unit about suspect matches, but he didn't see any disciplinary action against anyone.
"It soon became clear they didn't really want our advice on that or anything else," Phillips told the BBC.
Phillips wasn't alone in his criticism of the tennis body.
A former senior British police officer told the BBC's investigative partner, BuzzFeed News, that he wrote in a document to the ATP that the evidence supported his call for a more thorough inquiry.
"There was more concern over protecting the image of the integrity of their sport than doing their dirty washing in public," Kirby told BuzzFeed.
Kirby was referring to an investigation into a match between then world No. 4 Nikolay Davydenko and Martin Vassallo Arguello. Despite suspicious betting patterns, neither player was formally charged.
Kirby said the totality of the information led him to believe there was cause to start disciplinary hearings.
"When you have a number of threads of intelligence coming in, all relating to the same thing, then you've got an excellent reason to think there's some justification for this and you should then get your mind in order and investigate it," he told BuzzFeed.
The ATP and tennis' other governing bodies rejected claims of a cover-up or that evidence about match fixing was ignored.
The women's WTA Tour and the international ITF signed onto the statement, in which they said the associations "absolutely reject any suggestion that evidence of match fixing has been suppressed for any reason."
Match-fixing in tennis: ATP Tour rejects cover-up claim
The news comes as tennis' first Grand Slam of the year is being held in Australia.
Phillips told the BBC his group didn't just look at data but also examined some phone and computer records.
"The data analysts and investigators had linked players with the gamblers."
ATP head Chris Kermode said that six players have been banned from tennis, and there have been 18 convictions since the integrity unit was formed in 2008.
He told the BBC it is not in the interest of the integrity unit to suppress any information. He cautioned that not every case was as cut and dried as it might appear.
"I'm a strong believer that someone has to be proven guilty before we can suspend them," he said. "An alert about suspicious betting patterns doesn't mean that match fixing is necessarily happening."