Amazon Prime members are being told to look out for fake calls about their subscription, following reports fraudsters are impersonating the retailer to steal large amounts of money from victims.

Consumer organisation Which? is warning those who subscribe to Amazon's services, which include next day delivery and TV streaming options, to be aware of thieves who are ringing pretending to be from the online retailer.

Phone calls, imitating Amazon, are being made to people in the hope they can be tricked into downloading software that then gives fraudsters access to their devices.

In some of the worst instances, says Which?, unsuspecting victims have seen their bank accounts emptied by thieves after taking a call from someone who says they work for Amazon and that their subscription requires attention.

This scam, says Which?, will come from an unrecognised number and when the victim answers they are told their subscription is either about to run-out or rise in price.

Those who say they want to cancel or make changes to their existing deal are then told they'll need to be put through to someone else to discuss it, at which point they're reportedly passed to another fraudster who tells them to download remote access software.

In downloading the programme, criminals can gain entry to the victim's devices or install malware to cause further problems.

Amazon says it will never ask customers to provide remote access to their devices or make any payments outside of its website.

In a warning Which? advises: "If a fraudster has gained access to your device, you should be able to end the remote session by pressing a button that states ‘disconnect session’, or similar. Another option is to turn off your device and wi-fi to stop the fraudster in their tracks.

"When you turn the device back on, you can remove the software - look in your recent downloads folder to locate it. You should also contact your bank immediately as your account may have been accessed by the scammer."

Anyone who thinks they've been the victim of the scam is also asked to report the incident to Action Fraud on 0300 123 2040.