Police have smashed a gang of suspected metal thieves who allegedly worked with BT staff to steal thousands of pounds of underground cables throughout the capital.

Officers swooped on a Dagenham scrapyard yesterday in a bid to catch the gang red-handed as they allegedly followed a routine of exchanging tonnes of stolen BT cable for cash, police said.

The gang posed as roadside workmen in high-vis jackets who set up cordons around manholes to winch tonnes of underground copper cables used by BT, the Met said.

Detectives believe they received crucial tip-offs from the BT employees before embarking on expeditions that enabled them to successfully target specific sites all over London and the Home Counties.

It is thought they stole between one and three tonnes of BT cable each time, with each tonne worth between �6,000 and �10,000.

Four men and a woman, including a 25-year-old man from the Barking and Dagenham borough, were arrested yesterday in dawn raids at their home addresses in east London and Essex.

Two men were arrested at the scrapyard and two BT male employees were held at their homes in Hertfordshire and Essex.

Officers also seized a stolen BT Openreach van with two tonnes of copper cable worth around �15,000.

Police said the gang used the van on their regular expeditions to steal.

The raids followed a six-month intelligence operation by the Met’s London Crime Squad.

Det Insp John Cracknell said: “This criminal network is suspected of having made hundreds of thousands of pounds worth of profit from the illegal trade in stolen metal, helped considerably by the sensitive information we believe that the BT employees illegally passed on.”

A BT spokesperson said today: “BT has worked closely with the London Metropolitan Police, with our metal theft taskforce providing intelligence to assist with the police operation.

“BT will not tolerate any level of criminal behaviour, we will continue to work with police and do everything possible to catch cable theft criminals.”