Gambling syndicates contact tennis players in hotel rooms, offer $50,000 or more

Melbourne: "Secret files" leaked to website Buzzfeed News and the BBC have alleged widespread match-fixing and corruption in tennis.

Below is a summary of the main allegations:

-- Tennis governing bodies were aware of a core group of 16 players in world's top 50 involved in match-fixing. None have been sanctioned.

-- Eight of the 16 are playing in the Australian Open, the season's first Grand Slam, which began on Monday.

-- One top-50 player currently in the Australian Open is suspected of repeatedly fixing his first set in matches.

-- Match-fixing is orchestrated by gambling syndicates in Russia and Italy who contact players in hotel rooms and offer $50,000 or more.

-- The names of more than 70 players have appeared on nine leaked lists of suspected fixers, which were given to tennis governing bodies in the past 10 years.

-- After a 2008 probe, which implicated 28 tour players, all were allowed to continue playing without sanction.

-- Tennis Integrity Unit, which was set up to ensure fair play, admitted shelving the evidence of the 2008 report because a new integrity code they introduced afterwards "could not be enforced retrospectively".

-- The 2008 investigation was triggered by a notorious match between the world number four, Russia's Nikolay Davydenko, and Argentina's 87th-ranked Martin Vassallo Arguello, which attracted millions of dollars in highly suspicious betting on long-odds underdog Arguello to win from accounts originating in Moscow.

-- Davydenko was a set and a break up and cruising to victory when he pulled out injured. An investigation "was unable to find evidence" that either player had been involved in any corrupt practice.