Article continues below
Roger Federer will only believe accusations of widespread match-fixing in tennis when the perpetrators are named.
An investigation carried out by the BBC and Buzzfeed alleges that over the last decade a core group of 16 players have been brought to the attention of the sport's governing bodies over suspicions they have fixed matches.
The report claims all of the 16 players have ranked in the world's top 50 at some point and that more than half of them were playing in the Australian Open first round, which started on Monday.
The BBC said the group also included ''winners of grand slam titles'' but neither organisation named players, insisting it is not possible to determine whether they were personally taking part in match-fixing.
Federer answered several questions on the controversy following his first-round win over Nikoloz Basilashvili on Monday, but grew irritated when asked about the potential involvement of major champions.
''I would love to hear names,'' the Swiss said.
''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?
''It's so all over the place. It's nonsense to answer something that is pure speculation.''
The Tennis Integrity Unit was set up in 2008 to tackle corruption within the sport but the organisation's director Nigel Willerton refused to confirm whether players competing at the Australian Open are currently under investigation.
When asked whether paying lower-ranked professionals more might combat the threat, Federer responded to the journalist: ''I completely disagree with you. I think you don't understand.
''It doesn't matter how much money you pump into the system, there's always going to be people approaching players, or people, in any sport.''
Federer added: ''I agree we should have more money at Futures, Challengers, all these levels. But it's not going to solve the issue. The issue is elsewhere, it's in the player's mind.''
Novak Djokovic branded match-fixing as a "crime in sport" and confirmed he was offered ?110,000 in 2006 to lose a first round match in St Petersburg.
''I was not approached directly,'' Djokovic said.
''I was approached through people that were working with me at that time, that were with my team. Of course, we threw it away right away. It didn't even get to me, there was nothing out of it.''
Djokovic added: ''It made me feel terrible because I don't want to be in any way linked to this - somebody may call it an opportunity. For me, it's an act of bad sportsmanship, a crime in sport honestly.''
It is alleged that in 2007 tennis authorities were presented with an examination of 26,000 matches, three of them at Wimbledon, which contained enough evidence to root out offenders - but no action was taken.
Djokovic, however, insisted he is not aware of any match-fixing at the top level of the game.
Serena Williams said she has also never seen any indication of malpractice on the women's tour.
''Not that I'm aware of,'' Williams said. ''When I'm playing, I can only answer for me, I play very hard, and every player I play seems to play hard.''
Chris Kermode, president of the ATP which governs the men's professional tour, said the sport's authorities ''absolutely reject'' the suggestion that evidence of match-fixing has been suppressed.