The Cellmate, produced by Chinese firm Qiui, is a cover that clamps on the base of the male genitals with a hardened steel ring, and does not have a physical key or manual override.

The locking mechanism is controlled with a smartphone app via Bluetooth -- marketed as both an anti-cheating and a submission sex play device -- but security researchers have found multiple flaws that leave it vulnerable to hacking.

"We discovered that remote attackers could prevent the Bluetooth lock from being opened, permanently locking the user in the device. There is no physical unlock," British security firm Pen Test Partners said Tuesday.