The crooked tennis players knew him as "Maestro".
To European investigators, the Armenian based in Belgium is emerging as the suspected ringleader of an organised gambling syndicate suspected of fixing hundreds of matches and paying off more than 100 players from around Europe.
As Roger Federer and other stars at the top of tennis compete in the Australian Open, players far lower down the sport's food chain are being questioned this week by police in France on suspicion of fixing matches for Grigor Sargsyan, a 28-year-old known as the Maestro, investigators said.
Sargsyan is being held in a Belgian jail.
The picture emerging from months of investigations by police working across Europe is of a massive match-fixing scheme, organised via encrypted messaging, involving dozens of low-ranked players in lower-level pro tournaments with little prize money.
Police say Sargsyan employed mules, people hired for a few euros (dollars) to place bets for the syndicate that were small enough to slip under the radar of gambling watchdogs.
Sources close to the investigation said four French players were in police custody on Wednesday and at least one of them told investigators that he fixed around two dozen matches for Sargsyan.
They named the players as Jules Okala, 21; Mick Lescure, 25; Yannick Thivant, 31; and Jerome Inzerillo, 28.
None operated in the highest spheres of tennis.
A dozen or more other French players are expected to be questioned in coming weeks.
An investigator said France was one of the countries "hardest hit" by the syndicate but players in Belgium, the Netherlands, Germany, Slovakia, and Bulgaria have also been questioned.
In all, more than 100 players are suspected of having worked with the syndicate, fixing matches, sets or games in exchange for payments of 500 to 3,000 euros ($A800 to $4,750).
Sargsyan was swept up in a wave of arrests in Belgium last June and faces organised crime, match fixing, money laundering and forgery charges.
Still unclear is whether the Belgium-based syndicate was linked to another match-fixing and gambling operation, also involving Armenians, unravelled in Spain.
Spanish police last week announced that 28 professional tennis players, including one who participated in last year's US Open, were linked to that ring, taking bribes to fix results that the group bet on using fake identities.
