On Monday, the Australian Open kicks off tennis’s slate of 2016 Grand Slam events, one in which all may not be what it seems, according to a joint investigation by the BBC and BuzzFeed News. Their reports claim that match-fixing is widespread at the upper levels of the sport, and that a “core group” of players — eight of whom are set to compete in Melbourne — crop up repeatedly in instances of suspicious betting, but none has been sanctioned by tennis authorities.

Events that are cited as venues where match-fixing has taken place include Wimbledon and the French Open. In fact, the reports say that among the core group of 16 suspected players, all of whom have ranked in the top 50, are “winners of singles and doubles titles at Grand Slam tournaments.”

The reports didn’t name any of the players because “without access to their phone, bank and computer records it is not possible to determine whether they may have been personally taking part in match fixing.” But the BBC and BuzzFeed pointed out that, under an anti-corruption rule enacted by the sport’s governing bodies following a 2007 scandal, the Tennis Integrity Unit (TIU) does have the authority to demand such records from players.

That 2007 incident, in which highly ranked Russian Nikolay Davidenko withdrew from a match against Argentina’s Martin Vassallo Arguello amid a torrent of suspicious betting on the unheralded latter player, sparked an investigation into the match, which occurred at an ATP tournament in Sopot, Poland. Both Davydenko and Vassallo Arguello were eventually cleared of rules violations, but the probe widened to include a large number of players whose matches regularly seemed to involve suspicious betting patterns.

From the BBC’s story:

In a confidential report for the tennis authorities in 2008, the enquiry team said 28 players involved in these games should be investigated but the findings were never followed up. Tennis introduced a new anti-corruption code in 2009 but after taking legal advice were told previous corruption offences could not be pursued.
“As a result no new investigations into any of the players who were mentioned in the 2008 report were opened,” a TIU spokesman said.
In subsequent years there were repeated alerts sent to the TIU about a third of these players. None of them was disciplined by the TIU.

BuzzFeed developed an algorithm that analyzed bets placed on 26,000 tennis matches over the past seven years. Its report claimed that the algorithm “identified 15 players who regularly lost matches in which heavily lopsided betting appeared to substantially shift the odds.”

“Players are being targeted in hotel rooms at major tournaments and offered $50,000 or more per fix by corrupt gamblers,” BuzzFeed wrote. Three gambling syndicates, from Russia, Sicily and northern Italy, were cited as being behind many of the suspicious wagers.

“The Tennis Integrity Unit and the tennis authorities absolutely reject any suggestion that evidence of match fixing has been suppressed for any reason, or isn’t being thoroughly investigated,” ATP CEO Chris Kermode said in a press conference at the Australian Open. “And while the BBC and BuzzFeed reports mainly refer to events from about 10 years ago, we will investigate any new information. We always do.”

“The evidence was really strong,” Mark Phillips, one of the investigators who contributed to the 2008 report, told the BBC. “There appeared to be a really good chance to nip it in the bud and get a strong deterrent out there to root out the main bad apples.”

“We are aware that it [match-fixing] is there, I think that it is on an incredibly small level, and it’s our business going forward that we keep acting on this in the best possible way,” Kermode said.