People in his party are known for receiving suitcases of cash (here, search for suitcase). Of course, they want to protect that.

By the way, Grasser was never sentenced for that, because while it's fishy as hell, it's not illegal, as long as the money can't be traced in either direction. At least he got thrown into jail for other corruption offenses in 2020, after about 15 years of court proceedings.