Seems a bit unusual that only the Gambling regulator has mentioned the criminal investigation. No comment or confirmation yet from the police as far as I can tell.
Does the regulator conduct and prosecute its own criminal investigations, like the UK Post Office does/did?
As others have stated, the police's social media feed usually goes into overdrive in situations like this. If they were trying to keep their actions low key, if indeed they are involved, then the regulator seems to have let the cat out of the bag.
Probably a huge coincidence, but in the couple of days leading up to yesterday's regulator's announcement, five people, including two in the UK, have been detained for allegedly spying for China - https://www.aljazeera.com/news/2024/4/22/germany-detains-three-suspected-chinese-spies