She is the smart, talking doll that “you can talk to like a real friend”. According to child safety campaigners, however, My Friend Cayla may also be a spy.

The doll was launched in 2014, one of a new generation of internet-enabled toys that relies on an app and a Bluetooth connection to deliver realistic responses to children’s questions.

The “world’s first ‘live’ interactive doll” was a Christmas bestseller and is available in the UK from £29.99. However, a coalition of campaign groups has lodged a complaint with the Federal Trade Commission in Washington DC, alleging that the doll maker, Genesis Toys, is effectively spying on young children.

The toymaker has been accused of recording the voices of children and sending them to a software company that sells “biometric solutions” to law enforcement and the military.

“[Toys such as these] pose an imminent and immediate threat to the safety and security of children in the United States,” the complaint said. Campaigners also argued that programmed answers on some dolls were a deceptive form of product placement.