The investigation is led by Gloucestershire Constabulary's Serious and Organised Crime Unit.

A sixth man from London has admitted his involvement in a telephone scam to defraud victims across the country by posing as police officers.

Mohammed Ahmed 34 of Quex Road, Kilburn appeared at Gloucester Crown Court on Wednesday (November 10).

He admitted being involved in a conspiracy to commit fraud by misrepresentation, namely falsely alleging to be police officers involved in an investigation of offences in relation to bank accounts intending to make a gain, namely money, for themselves and others between 1 January and 6 April this year.

Five other men from London pleaded guilty to similar charges at previous hearings. All six have been remanded in custody and are due to be sentenced at a date to be fixed.

The investigation led by Gloucestershire Constabulary's Serious and Organised Crime Unit resulted in warrants being executed in London in April and May of this year with cash, designer clothing, Rolex watches and two vehicles being seized.

The case relates to in excess of 60 victims, some aged in their 90s, losing thousands of pounds after people were targeted in scam phone calls. The victims are from across the country and numerous other forces supported Gloucestershire's investigation.

Following the hearing Detective Inspector Matt Phillips from the Serious and Organised Crime Unit said: "This is a complex case where the group from London worked together to target and defraud people across the country.

"This is a particularly callous crime as it not only has a huge impact on someone's finances but can also have a huge impact on their mental health.

"People who are scammed often feel understandably distressed that they have been deceived in such cruel a way - the fraudsters are extremely manipulative and rely on people's goodwill and trust of the police.

"In this case the group made thousands of phone calls, using fake stories to defraud the most vulnerable in our communities.

"Sadly, we see this type of crime far too often, and I would urge you to make your elderly relatives, friends and neighbours aware of this scam which anyone could fall victim to."

Be aware:

• Neither police nor bank officials will ever ask you to withdraw money from your account, purchase anything or hand over your personal details or passwords.

• If you believe you are being targeted by a scammer hang up the phone and use a different phone line to call Action Fraud or the police, as scammers have a way to stay on the line and will pretend to be the police when you call back.

• If you don't have access to a different phone line, wait for a period of time and try calling a family member or friend first to make sure the scammer is no longer on the line.

• Just because someone knows basic details about you like your name, address or date of birth, it doesn't mean they are genuine bank or police employees.

• Always question suspicious phone calls and report them to Action Fraud or the police.

If you think you or someone you know has been defrauded, you can report it to Action Fraud  online or by calling 0300 123 2040.