Durham police officers have been given training to detect signs someone could be a paedophile by looking at indicators such as clothing and certain types of tattoos.

The force has put 400 officers through the Intervene to Protect a Child (IPC) programme developed in the US by the Texas Rangers with the involvement of Dr Joe Sullivan.

Dr Sullivan is an expert who has assisted with investigations into the disappearance of Madeleine McCann and the murder of April Jones.

The programme teaches non-specialists certain behavioural signs that someone might be a child abuser, which include certain types of tattoos, photographs and even books.

One officer, PCSO Adam Grundy, 28, said he put his training to use within just two weeks and protected a girl under five who was at risk.

Mr Grundy was concerned about an elderly man who he regularly saw, when he spotted a condom and a Viagra tablet in his property during a routine call.

The PCSO established the man, who had a history of sexual offending against children, was visited by a woman with a young child. He contacted Social Services and the man was barred from seeing the child.

Mr Grundy said: "This guy was being very evasive with me when normally he would engage. He was very stand-offish and wanted me to leave.

"His personality had completely changed and that was something I referred back to in my training."

Durham Constabulary Chief Constable Mike Barton said he was “absolutely delighted” that Durham Constabulary is the first force in the UK to adopt the training.

"We are giving them the confidence to recognise, if people wear certain clothing, if people have certain tattoos, if people behave in a certain way, that might be an indication,” he said.

He did not elaborate on what kind of tattoos or clothing could be used to detect a potential child abuser.

"When you add these things together, that should give them the confidence to a frontline member of staff to do a bit more digging.

“As a result I’m convinced that my officers on the frontline will be better equipped to spot the vital signs which may protect a child from harm.”

Dr Sullivan said his knowledge of the hidden behavioural signs of paedophiles has come from interviewing thousands of abusers.

He said: "I have learned from that they have had to say, what are the key indicators that someone who may not have that level of knowledge may not pick up on.

"This training is about targeting frontline staff who are not working in the arena of child sexual exploitation."