Child abuse whistleblowers should have immunity from arrest, says Theresa May

Home Secretary's remarks following claims that officers investigating the activities of the late MP Sir Cyril Smith were threatened with court action under the Official Secrets Act

Police and intelligence officers with information about paedophile rings should be protected from prosecution if they appear before the official inquiry into historic sex abuse, Theresa May has said.

The Home Secretary backed immunity for witnesses following claims that officers investigating the activities of the late Liberal MP Sir Cyril Smith were threatened with court action under the Official Secrets Act.

Scotland Yard is being investigated over allegations it covered up child sex abuse because of the involvement of MPs and police officers.

A former detective has claimed that the politician escaped prosecution because other Establishment paedophiles feared he would reveal their identities in court and said he was ordered to drop his investigation into Smith.

Ms May told MPs there “seems to have been a cover-up” and hinted that the IPCC (Independent Police Complaints Commission) investigation could result in criminal prosecutions.

She said the Northern Ireland judge heading the investigation into claims of abuse over two decades at the Kincora boys’ home has said no one would be prosecuted for giving evidence.

The Home Secretary said she had written to Justice Lowell Goddard, who is conducting the main inquiry for England and Wales, suggesting she follows suit.

She warned the Commons Home Affairs Select Committee that she expected further grim disclosures about the systemic abuse of youngsters.

“I think what we what have seen so far is the tip of the iceberg and society will be shocked when they see to what extent this is an issue around the UK,” she said.

Detectives were told to stop investigating Cyril Smith on suspicion of child abuse (Getty) (Getty Images)

Jack Tasker, a former Lancashire detective sergeant who investigated paedophilia allegations against Smith, said the MP could have exposed other high-profile abusers if he had been taken to court.

Mr Tasker said that when he interviewed Smith over allegations at the Cambridge House care home in Rochdale 45 years ago, he was a “frightened man” who was “sweating profusely”.

Smith admitted stripping boys and carrying out what he described as “medical examinations,” although he acknowledged he was not medically qualified.

“He used his position in Rochdale to do as he liked,” the detective told Sky News. The investigation was stopped because he believed “other people were worried that if Smith went before a court, he would open his mouth”.

Mr Tasker said as he walked out of the interview room, Smith commented: “This will kill my mother.”

He assumed those who stopped the investigation were from Special Branch and they demanded all their notes and records from the investigation to be handed over and told to go no further.

Two earlier investigations had taken place by the former Rochdale borough police force. Smith, who died in 2010, was accused of eight counts of sex abuse and six offences at a care home, which his family say he always denied.

Tom Watson, the Labour MP who first spoke out in Parliament about the matter in October 2012, today called on David Cameron to shield whistleblowers from that law.

Mr Watson said: “The Prime Minister must guarantee that former police and intelligence officers who wish to help the IPCC with their inquiries will have the threat of the Official Secrets Act lifted.”

It is claimed that police officers brought Smith in for questioning in connection to an inquiry in the early 1980s into properties in south London suspected of hosting paedophile parties.

He was released within hours of being taken to a police station and officers were ordered to hand over notebooks and video footage, according to the claims.