Detective Inspector Stuart Mellish, heading up the operation said: “These arrests follow a complex eighteen-month investigation by officers from Operation Leopard.

“We believe this organised gang have been working together to steal cable, valued in the region of over £2m, from across England over the past two years.

“Railway cable theft is blighting our infrastructure and disrupting the lives of ordinary people on a daily basis, but we have teams of officers dedicated to tackling the problem and who have been really effective.

“Recently we’ve seen significant reductions in cable-related offences on the railway in the North East – a 69% reduction, which is great news.”

DI Mellish added: “We’re also arresting more and more thieves and putting them before the courts. However, we’re not complacent and, as today’s operation shows, our work to tackle these suspected thieves will continue.

“I’d like to thank members of the public for their ongoing support in helping us in tackling this crime and ask that people continue to report any suspicious behaviour near the railway, or in their communities, to police so we can work together to drive this crime down further.”

Fourteen people, 11 men aged 43, 42, 41, 38, 37, 36, 30, 28, 28, 25, and 24, and three women, aged 27, 27 and 18, were arrested in the Sunderland area. A 50-year-old man was also arrested in Osmotherley, North Yorkshire.

Prior to their arrest today, four of the men, aged 38, 28, 28 and 41, were arrested on Saturday, 23 March 2013 in connection with the theft of 750 metres of railway cable from the Manton Lane area, near Crossgates, Leeds.

They were detained after two vehicles they were travelling in were intercepted on the M1 motorway near Harrogate.

Both vehicles were seized, and a number of items were taken for forensic examination following a search of the vehicle and their home addresses, including mobile phones, laptops, clothing, and cutting tools.

All four men were questioned and released at that time on police bail pending further enquiries until 24 April 2013. They have now been further arrested on suspicion of other offences and remain in custody at this time.