Spanish police 15 people, including some professional tennis players and the suspected leaders of the criminal organization, involved in "manipulation of professional tennis competitions," Europol said in a statement on Thursday. An additional 68 people are under investigation.

Professional tennis' anti-corruption body last year complained about irregular activities at games, including prearranged matches, at the lower-tier ITF Futures and Challenger tournaments.

"Our officers have proved the group had been operating since February 2017 and estimate that they had earned millions of euros through the operation," Spain's Civil Guard said in a statement.

Read more: Dirty Games - The Dark Side of Sports

What we know so far:

Spanish police raided 11 houses. They confiscated €167,000 ($191,000) in cash, a shotgun, more than 50 electronic devices and five luxury vehicles, as well as other valuables. At least 42 bank accounts were frozen.

The Armenian gang bribed players into fixing matches, according to authorities. The criminal group would then use the identities of thousands of citizens to bet on the games.

Gang members would attend the matches to ensure the player complied with the prearranged results. They also gave orders for "other members of the group" to place bets at the "national and international level."

Europol provided support, including sending three experts to Spain to provide "on-the-spot assistance including real-time cross-checks, IT forensic support and data analysis during the operation."

Read more:FBI probes Adidas in basketball bribery case

Every evening, DW's editors send out a selection of the day's hard news and quality feature journalism. You can sign up to receive it directly here.

ls/msh (AP, Reuters)