In a statement, the Civil Guard police force said the organisation bribed tennis players to fix matches in ITF Futures and Challenger tournaments, the lower levels of professional tennis where young players start out before getting to the ATP level.
The Civil Guard added the operation kicked off after the Tennis Integrity Unit, an anti-corruption tennis body, made an official complaint.
It did not identify those detained or being probed but said one of them played in the last US Open. It is unclear whether he is among the arrested or investigated.
According to Europol, “the suspects bribed professional players to guarantee pre-determined results and used the identities of thousands of citizens to bet on the pre-arranged game.”
The members of the organisation are Armenian. “Some of them” were arrested, a Civil Guard spokeswoman told AFP.
They “attended the matches to ensure that the tennis players complied with what was previously agreed, and gave orders to other members of the group to go ahead with the bets placed at national and international level,” Europol said in a statement.
The Civil Guard said the group had been operating since at least February 2017 and could have made millions of euros.