A YOUNG couple with a small child have escaped with pensioners' cash in two bogus caller thefts.

Durham Police have launched a campaign, backed by comedian Ken Dodd, to encourage old folk not to let strangers into their homes.

The comic's picture will feature on 270 bus posters with the message: Happiness is keeping your home safe and secure, don't let strangers in.

The force's head of community safety, Chief Insp Andy Reddick, said: "Ken Dodd is a very recognisable face and we think our target audience will relate to him. He is, of course, a very funny man but in this instance he is helping us get across a serious point."

But on Monday two incidents occurred in Durham that police believed may be linked to others on Tyneside and Wearside. A man in his 20s with a girl of about seven called at an elderly woman's home in the Springwell Avenue area, claiming to be collecting jam jars.

The child asked for a drink of water and she and the man also asked to use the toilet. They left, taking a shopping bag, which included a purse containing £20.

Later a man and a woman in their 20s, again with a child, called at a ground-floor flat in The Chains, claiming to be charity collectors. The girl asked for water but the occupants refused to let them in and kept them at the door.

The trio went to a flat upstairs and were allowed in and after distracting the two pensioners took a wallet containing cash. Police believe the same people were involved in all three incidents and that they may have been responsible for stealing a purse in Chester-le-Street on October 23.

Det Chief Insp Andy Summerbell said: "Our advice to the public is when callers arrive unannounced and say they are from the water board, electricity board, council, or, in this case from a charity, they should be kept at the door until their credentials can be checked and verified.''

The man is 25 to 30, 5ft 4in to 5ft 6in, slim and with thick curly hair. The woman is about the same age, 5ft 2in to 5ft 4in tall, with black hair and brown eyes.

The girl is seven to nine, with black collar-length hair and brown eyes. All had local accents.

Anyone with information should call police on (0191) 386 4929 or Crimestoppers on (0800) 555 111