An undercover policeman seeking to track down a drugs gang had a lucky break when he gave a lift to a hitch-hiker who was a heroin addict being supplied by them, a court was told yesterday.

The addict was distressed about the death of a friend who had died from drugs and he had been beaten up by three men. The officer gave him a lift home and a friendship developed, said Michael Bosomworth, prosecuting.

The officer was just starting what became a nine-and- a-half-months operation, in the Shildon and Aycliffe areas of County Durham, involving extensive surveillance and telephone tapping.

He told the addict he was keen to buy some drugs and the man led him to contacts which helped to put three men and a woman behind bars for more than 20 years, said Mr Bosomworth.

Heroin deals were done in the officer's car and they even shared two bags of heroin which were bought in Dead End Road, in Shildon.

The addict, Anthony Dawson, 24, introduced him to various suppliers and told him: "We will go through to Shildon. The bags are better there," Teesside Crown Court was told.

Rod Hunt, defending, said that Dawson was a vulnerable person and easily influenced.

Mr Hunt said: "His motivation was to help a fellow addict. He was the key which the police used to unlock the door. He is a bit of a lost soul and he had been living from hand to mouth."

Dawson, of Front Row, Eldon Lane, near Bishop Auckland, was remanded in custody for three weeks for hostel suitability reports after he pleaded guilty to conspiracy to supply heroin.