Lisa Neilson, a 34-year old mom from Castleford, West York, bought a gel cover from eBay to protect her new S10.
She used her right thumb print to access the phone but found later that the device could be unlocked with her left thumb as well.
“Anyone can access it and could get into the financial apps and transfer funds.”
When her husband Wes, 34 tried with both his thumbs, he was also able to open the phone through the gel cover.
Lisa also checked her sister’s Samsung and the results were the same when with the case on.
Samsung is now investigating the issue.
“This means that if anyone got hold of my phone they can access it and within moments could be into the financial apps and be transferring funds.
“It’s a real concern.”
“We called Samsung because we thought there was a fault with the phone.
“The man in customer services took control of the phone remotely and went into all the settings and finally admitted it looked like a security breach.
“They said someone in another department who could investigate would call us but we still haven’t heard anything from them.”
A spokeswoman from Samsung said:
“We’re investigating this internally. We recommend all customers to use Samsung authorised accessories, specifically designed for Samsung products.”