Agas are at risk of being turned on an off by hackers, a security researcher warned after discovering a problem with the company's high-end cookers.

Ken Munro, a security researcher at Pen Test Partners, has criticised Aga over the safety of its range of ovens that can be controlled using an app. He was considering upgrading his Aga to the app-controlled version of the oven, which has been available since 2012, when he discovered a problem that could let hackers turn people's ovens on and off without them knowing.

"I wanted to know more about its security before spending extra on this option," said Munro. "We found that even Agas can be hacked. Seriously."