Certain criminal groups that deal with Orginized crime, like an Italian mafia for example rely heavily on corrupt officials to operate realisticly. Without having the ability to at least somewhat influence police their gameplay would be extremely linited

Could this not be solved by allowing for Police forces to engage in behind the scenes corrupt game play but having some sort of federal agency or Internal Affairs that was forbidden from engaging in any kind of corruption, whose sole purpose was rooting out corrupt officers?