The investigation is into the alleged cover up of a paedophile ring within Westminster, there absolutely needs to be one. A conspiracy to protect high ranking politicians and Lords involving the police and other branches of government needs to have the light of day shone on it and the people involved prosecuted.
Not having an investigation would be negligent, and I don't believe the investigation into the voice mail shit was necessary, the existing laws were more than enough to get a conviction of the perpetrators, and nothing has been done about bent coppers after all of the fall out. This time though, there definitely needs to be one, a state sponsored cover up of paedophilia in Westminster is explosive stuff and the government can't afford to kick the can down the road.
So far we have Westminster, the Catholic church, the BBC, local government and the NHS involved. There are implications that the police hushed it all up as well so we can count Scotland Yard in as well. Hodges, unsurprisingly, is wrong.