LONDON (AP) — Seven Belgian tennis players have been suspended from the sport as part of a match-fixing investigation, the International Tennis Integrity Agency said Friday.

The ITIA said the players admitted to corruption breaches and that the sanctions "are linked to a recently concluded criminal case involving a match-fixing syndicate" in Belgium.

"Collaboration between the ITIA and Belgian authorities led to a five-year custodial sentence for the leader of the syndicate, Grigor Sargsyan," the ITIA said.

The suspended players are Arnaud Graisse, Arthur de Greef, Julien Dubail, Romain Barbosa, Maxime Authom, Omar Salman, and Alec Witmeur.

The ITIA said the players were "convicted by the criminal court and have subsequently agreed sanctions with the ITIA."

The suspensions range in length from two years, seven months up to four years, 10 months.

The 31-year-old De Greef reached a career-high ATP singles ranking of No. 113 in 2017. He admitted to nine breaches and was suspended for three years, nine months. He was also fined $45,000 with $31,500 suspended.

"These sanctions conclude ITIA proceedings against Belgian players in relation to the Sargsyan match-fixing ring, though syndicate cases relating to players from outside Belgium remain ongoing," the ITIA said.