The first sniffer dogs trained to help police catch paedophiles, terrorists and fraudsters by detecting hidden digital storage devices have been unveiled in the UK.

Tweed, a 19-month-old springer spaniel, and Rob, a 20-month-old black labrador, are understood to be the first digital detection dogs outside the US.

The dogs, which were trained by the FBI, have already been used in over 50 raids by other UK forces in Essex, South Wales and North Yorkshire.

They have been taught to sniff out devices such as USB sticks, SD cards and hard drives, used by criminals to stash sexual images of children or information about secret drug dealing and financial networks.

In one raid Tweed pointed out to officers what looked to be a cola can. However, on closer inspection it turned out to be a money box which had a number of SD cards hidden inside.

Chief Superintendent Jim Nye, who combines joint operations between Dorset Police and Devon & Cornwall Police, said: "These dogs will give the police a new way to fight the threat of terrorism, paedophiles and fraudsters.

"We have shown that we are prepared to look at new technology and will always strive to get one step ahead to tackle criminality."

The two digital dogs are part of a trial, that will police will assess their success until the end of the year, before considering a rolling out the scheme to more forces across the country.

Both dogs received specialist training in the US on how to detect a chemical used to cool digital memory chips.

Special agent Jeffrey Calandra of the FBI added: "In today's tech-driven world crime has no state or even country boundaries, so helping our law-enforcement partners around the world develop cutting edge detection capabilities is key to fighting crime and terror."

The dogs are based with Dorset Police and Devon & Cornwall Police, and live at home with their new full-time handlers PC Martin King and PC Jill Curnow.