hospitals prisons, the military. Some 200 are now dead. Chief Constable Simon Bailey is leading the inquiry code-named Operation Hydrant.

CHIEF CONSTABLE SIMON BAILEY: It gives you some idea of the scale of the challenge that we're facing because this simply cannot be simply about the police service. It is far, far broader than that.

BARKER: The police haven't always been part of the solution. There are allegations that senior officers helped quash previous investigations.

(SOUNDBITE OF WATER RUNNING)

BARKER: Three bronze dolphins cavort in the courtyard fountain at Dolphin Square, a stone's throw from Parliament and the government ministries of Whitehall. This vast 1930s apartment complex has long been a bolt-hole for the British establishment, but Dolphin Square is also one of several addresses across London where one pedophile ring, comprisingsome of Britain's most powerful men, allegedly abused underage boys in the 1960s, '70s and '80s, boys as young as 6 bused in from care homes or the slums. There are tales of orgies and even one allegation of murder.

(SOUNDBITE OF ARCHIVED RECORDING)

UNIDENTIFIED WOMAN: Why would the state chose systematically to protect VIP pedophiles?

BARKER: In March, the BBC reported that an undercover police team investigating the ring in the early 1980s was ordered to hand over all of its evidence and the officers threatened with prosecution under the Official Secrets Act. James Badenoch is a senior British lawyer who has handled a number of cases involving the sexual abuse of children.

JAMES BADENOCH: The idea that they were terrorized in the way alleged doesn't surprise me at all. What