The Swedish Police have arrested of five people in Stockholm in connection to a tennis match-fixing investigation.

The National Operations Department (NOA) carried out the arrests today (April 14) following an ongoing investigation by its anti-corruption group. The NOA also searched several homes.

The alleged match-fixing is said to involve substantial sums of money, though the amount was not revealed.

The Swedish Police Authority previously condemned match-fixing as a “significant threat” to sport.

“We can see that all sports risk being affected by match-fixing, and we work intensively against this through, among other things, preventive efforts and collaboration at several different levels to access the problem,” says Stefan Erkensjö of NOA’s anti-corruption group.