Police are using special slow-moving trains to help catch metal thieves blighting the rail network.

Undercover officers from the British Transport Police (BTP) travelled between Shoebury and Upminster at 34mph, using a heat seeking camera to snare thieves stealing copper cables.

The team was deployed last week during a series of nighttime ops in theft hotspots.

A spokesman for the BTP said: “The trains normally travel at around 65 to 70mph in that area so when the slow-moving trains creep along at 34 mph it hardly makes any sound and it can take suspects by surprise.

“We dim the lights in the train and our officers sit in the front with heat-seeking cameras - if they spot anything suspicious they hop out and investigate.”

A 28-year-old man from Grays, Essex, was arrested at home in the early hours of Thursday April 7 on suspicion of attempted theft of cable, and resisting arrest on the January 24.

More than 40 BTP officers, aided by police sniffer dogs and helicopters, worked along the lines running between east London and Essex; London and Reading; and West Coast Mainline and Northampton.

The action, codenamed Operation Historian, aims to tackle the increase in cable theft which causes train delays and cancellations.

Supt Paul Brogden, who led the operation, said: “This sends a clear warning now to all would-be cable thieves – not only are you risking your life, you stand a very high chance of getting caught in what is a highly-policed environment.”

“The theft of railway cable can – and does – result in lengthy delays and cancellations to rail service, whilst theft of other items such as residential earthing cable or communications cable can have a serious impact on people’s homes and businesses.”