Andrew Mitchell could return to Government, minister suggests He failed to rule out a return to the Cabinet for Mr Mitchell after a full investigation is completed. "There have been four arrests so clearly the police are taking this seriously," Mr Shapps told Sky News. Information has been handed over to the Crown Prosecution Service. This is part of an ongoing investigation and we'll have to see where it ends. Naturally if what is being alleged is true and there was a sort of cover up or attempt to fit him up then that's a very serious matter. Mr Mitchell has been critical of Number 10 over the failure to more quickly release the security camera footage which cast doubt on elements of the accusations against him. Asked if he would welcome his former colleague back into the Government, Mr Shapps said: "He was working very hard in his job. It's come to an incredibly abrupt end. He clearly has many concerns. The police clearly have concerns otherwise they wouldn't have had four arrests. So let's wait and see where this ends up. But this is clearly a very serious matter: We can't have, in a democratic country, these types of things happening. We want to see what the outcome of that whole process is and then we'll see what happens with Mr Mitchell in the future. Mr Mitchell has written to the Independent Police Complaints Commission (IPCC) accusing the Metropolitan Police of a continued campaign to "destroy" his career. He took the action after newspaper reports suggested a police file passed to the Crown Prosecution Service contained no evidence that officers lied about his behaviour. In a letter to IPCC deputy chairman Deborah Glass, he wrote: "We are deeply dismayed that the Metropolitan Police appear to have leaked part of their Report prepared for the Crown Prosecution Service (CPS) to certain members of the Press and spun it to the advantage of the Police officers involved. This was an Enquiry into a dishonest and illicit attempt to blacken my name and destroy my career. It would appear that this police enquiry continues precisely that process. Keith Vaz, Labour chairman of the Commons home affairs committee, said the latest development showed it was wrong for Scotland Yard to lead the inquiry into its own officers and called for the whole investigation to be taken over by the IPCC. Three officers from the Diplomatic Protection Group have so far been arrested as part of the investigation. All three remain suspended. Some 30 detectives have taken statements from all 800 officers in the DPG, which is tasked with protecting government officials. Papers related to the case were passed to prosecutors on Thursday, but the CPS said it was not "a full file of evidence" and that is expected more. A number of newspapers have reported sources as saying the file did not contain any evidence to back Mr Mitchell's claim of a conspiracy by officers.