How do you get our own Government Investigated at the very highest level

It seems like The FBI are doing a massive International investigation on FIFA. So what do we do as a country when there are massive allegations about Various ministers and MP's who are alleged to have been involved not just in Child Abuse, but Torture and Murder as well. Google... Edward Heath, Jimmy Saville, Haut de Garenne. So we have an ex Prime Minister, Home Secretary, various MP's of all parties, members of the renowned Monday Club, Entertainers, Members of the Judiciary, all alleged to have been involved in this. D Notices, The Secret Service, Special Branch are also accused of colluding, covering up and protecting these people. So is it any surprise that various inquiries are continuing to white wash what has been happening. So do we need to appeal to the FBI to investigate these accusations, they are doing a great international job of Investigating FIFA. The thing is how do we get action when our own Government is so heavily involved in covering all this up, they don't want to get to the truth because it will bring down The Government. How do you get our own Government to the very highest level investigated. ?