A BBC and Buzzfeed report over tennis fixing shook the sport only hours before the first grand slam in Australia kicked off Sunday night.

The report did not name big names. But No. 1 Novak Djokovic has admitted gamblers asked his staff to make him throw a first-round match in Russia.

In 2007, someone approached a member of Djokovic’s team about the set up. But they immediately turned the fixer down.

“I was not approached directly. I was approached through people that were working with me at that time, that were with my team,” he explained. “Of course, we threw it away right away. It didn’t even get to me, the guy that was trying to talk to me, he didn’t even get to me directly. There was nothing out of it.”

The news outlets stated that at least “16 players who have ranked in the top 50 have been repeatedly flagged to the Tennis Integrity Unit (TIU) over suspicions they have thrown matches.” These players include winners of Grand Slams.

However, the BBC and Buzzfeed did not name any of the big names. But the details showed the reporters that “betting syndicates in Russia, northern Italy and Sicily” existed, which made “hundreds of thousands of pounds betting on matches investigators thought to be fixed.”

Three fixed matches occurred at Wimbledon, but neither outlet specified which ones.

“Unfortunately there were some, in those times, those days, rumours, some talk, some people were going around. They were dealt with,” continued Djokovic, adding:

In the last six, seven years, I haven’t heard anything similar. It made me feel terrible because I don’t want to be anyhow linked to this kind of opportunity. For me, that’s a crime in sport honestly. I don’t support it. I think there is no room for it in any sport, especially in tennis.

I always have been taught and have been surrounded with people that had nurtured and respected the sport’s values. That’s the way I’ve grown up. Fortunately for me, I didn’t need to get directly involved in these particular situations.

Djokovic insisted match fixing does not include the top players or occurs at the top level.

“Challenger level, those tournaments, maybe, maybe not,” he said.

No. 3 Roger Federer pushed the publications to reveal the names.

“I would love to hear names,” he told the press. “Then at least it’s concrete stuff and you can actually debate about it. Was it the player? Was it the support team? Who was it? Was it before? Was it a doubles player, a singles player? Which Slam?”

He added: “It’s super serious and it’s super important to maintain the integrity of our sport. So how high up does it go? The higher it goes, the more surprised I would be.”

Buzzfeed claims:

A 2008 probe showed tennis authorities they needed to investigate at least 28 players, but they never took action. They implemented an anti-corruption in 2009, but legal said previous actions “could not be pursued.”

In 2008, a match between then-No. 4 Russian Nikolay Davydenko and Argentine Martin Vassallo Arguello “triggered” the investigation. From Buzzfeed:

The tennis authorities announced at the end of the investigation that they had found no evidence of rule-breaking by Vassallo Arguello or Davydenko. But the files reveal that Vassallo Arguello had exchanged 82 text messages at a previous tournament with the suspected ringleader of an Italian gambling syndicate that made hundreds of thousands of pounds betting on his other matches. Inquiries into the Russian gamblers who placed suspicious bets on Davydenko stalled when one threatened violence. These Italian and Russian gambling syndicates and another in Sicily were found to have placed suspicious bets on 72 matches involving the 28 players that the investigators flagged to the authorities.

The four governing bodies (ATP, WTA, Grand Slam Board, ITF) rejected the evidence provided by the BBC and Buzzfeed. Chris Kermode, the executive chairman of the ATP and Tennis Integrity Board member, claimed the sport has “stringent procedures and sanctions in place to deal with suspected corruption.”

“No player or official is immune from investigation, regardless of their status or position in the sport,” he declared. “Investigations follow where evidence leads.”

He continued: “No player or official is ever cleared by the TIU of potential involvement in corruption. By its very nature, corruption is difficult to prove, so while the process can be lengthy, the TIU will continue to pursue evidence where it believes it is warranted.”