Researchers have suggested that the factory reset option is faulty on a number of Tesco Hudl & Android devices, with potentially sensitive information being accessible.

Three separate investigations successfully recovered information on second-hand Android devices sold via auction websites.

The inquiries found that often a reset simply removed a list of where data was stored – leaving the files untouched.

It was also discovered that the Tesco Hudl tablet was found to have a flaw that lets attackers exploit a known bug in the Rockchip processor, to read and write to its onboard memory, accessing files even after a factory reset.

The researchers were also able to extract PIN codes, Wi-Fi keys, cookies and allow the hacker to use websites, such as social networks, posing as the original owner.

A Tesco spokesperson said: : “Customers should always ensure all personal information is removed prior to giving away or selling any mobile device. To guarantee this, customers should use a data wipe program.”

The spokesperson also stated that any Tablets returned to Tesco would have their personal data wiped.