Police have issued a warning after a female fraudster posing as a police officer targeted elderly and vulnerable people across Essex with phone scam.

A woman calling herself Jennifer Clark, or Jennifer Lark, has posed as a police officer and tried at least 12 times in the last two weeks to steal bank cards and cash.

She made four calls yesterday, but all intended victims realised the caller was bogus and contacted police.

Detective Sergeant Neil Hudson said: "She always claims to be an officer from the local police station and says she is investigating burglaries in the area.

“She tells her intended victims that her bank cards have been found as a result of enquiries into the burglaries before asking them to let police have bank or credit cards or cash for forensic examination.

"A courier is then sent to pick up the cards and cash but they are never returned.

A total of 750 similar thefts and attempted thefts using the technique have been reported in Essex since the January 2013.

More than 100 people in Essex have been tricked out of money and the total stolen is more than £355,000.

Police have told the public to remember police or bank officials would never call them and ask for full bank details or to withdraw large sums of cash.

They also advise calling police from a different number or using a neighbour’s phone.