A warning has been made following numerous reports of telephone fraud targeting elderly or vulnerable victims.

Reports have been received through West Mercia - including in Shropshire where two men claimed to be undercover police officers from Scotland Yard investigating a fraud. Their target was a man in his 70s who was asked to withdraw and hand over a substantial amount of money for them to investigate.

The incident happened on Thursday, March 15.

Although the detail of each report varies, all involve a caller pretending to be from HMRC or the police persuading the call recipient to hand over bank details, personal details and/or money.

The incidents are being investigated under Project Prospero, an ongoing West Mercia Police operation working in conjunction with Action Fraud - the UK's national fraud and cyber crime reporting centre.

Inspector Emma Wright, of the West Mercia Police Economic Crime Unit, said: "Please remember that no legitimate bank/building society, police officer, government organisation or business will ever phone you to ask you to give them your card, your PIN, or your cash in the way we've described.

"The incidents we're investigating under Project Prospero are all deliberately targeted at older or vulnerable people, which makes them particularly cruel and immoral.

"Often, the phone caller will tell the victim their bank account has been subject to a fraud and that they must cooperate with an 'investigation'. The victim is then persuaded to withdraw funds and hand them over to the 'investigators', either by some remote means or in person to a courier. Alternatively the victim may be asked to hand over bank cards, vouchers or other valuable items. They may also be asked to transfer funds to another account, which is controlled by the fraudsters.

"These scams can be extremely convincing and manipulative. The fraudsters may give (alleged) crime numbers, investigation details, and job titles. They will always claim that the transaction must be done in secret. The fraudsters condition their victim not to trust bank branch staff, which can make it hard for those staff to help."