Match-fixing in badminton may be more widespread than people think, world top 10 men's player Hans-Kristian Vittinghus told Kyodo News in a phone interview.

Vittinghus, who is also vice president of the Danish Badminton Athletes Commission, said that a few days before the Japan Open in June 2014, he was studying in his hotel room when he received a Facebook message from a man he had met at previous tournaments.

The man first asked if he was in Japan and ready for the tournament, but then the conversation took a sudden turn.

"The next thing he said was he knew a guy, a bookie who was fixing matches, if I had any interest in doing that," Vittinghus said. "Of course I declined straight away and said I was quite disappointed to be asked."

While Vittinghus was telling his teammates about the incident a few hours later, the man sent the same message to fellow Danish player Kim Astrup.

The players then agreed to gain as much information from the man as possible, reporting the incident to the Badminton World Federation's whistleblower system later that evening.

"We were just shocked that it's so close," Vittinghus said. "This guy said they had also fixed matches at the Singapore Open earlier that year, and also at the Thomas & Uber Cup."