A fraud victim was tricked out of £30,000 after a conman posing as a police officer warned he would be arrested if he failed to hand over the cash.

The sum is one of the largest amounts taken in the UK through a telephone scam carried out by organised crime gangs.

The victim, who is in his 60s and lives in Chigwell, was contacted by a man claiming to be a police detective.

He was told that criminals had infiltrated his bank account and had deposited £30,000 in counterfeit cash.

The fake officer then asked the man to take out the £30,000 so that it could be forensically examined.

The man was asked to call his bank to check that extra funds were in his account, but the original call had been kept open and the enquiry was answered by another fraudster, who confirmed that money had been deposited.

The bogus officer then called back and asked the man to withdraw £15,000 each from two branches in £20 and £50 notes.

He took out the money and told it would be collected, but became uncomfortable when the courier arrived and sent him away.

The fake detective then telephoned the victim and warned that he would be arrested for impeding a police investigation if he failed to hand over the cash.

Following the threat, he gave the £30,000 to the courier. Police have now released an e-fit of the courier.

The fraud happened on September 30 and the fraudsters have not been identified.

Detective Chief Inspector Paul Maleary, of Essex Police, said: "These criminals have become abusive in the past but this is the first time they have forced the victim to comply with their demands by making an arrest threat.

"This is one of the highest amounts taken in Essex and shows just how convincing these thieves can be. They are professional criminals and are absolutely ruthless.

"The only answer is to put the phone down and call Essex Police whenever you get any call asking for money to be taken out of your bank account.

"It is absolutely vital that people are reminded that your bank and the police would never ask for your bank details, ask you to withdraw money or send them bank cards.”

More than 800 similar thefts and attempted thefts have been reported in Essex since the scam first came to light in January 2013.

More than 140 people in the county have been tricked out of money and the total stolen is more than £500,000.

Anyone who can identify the man in the Efit is asked to contact the investigating officer PC Danielle Brennan at Loughton on 101.