But Dr Barber said the robots would effectively become an “extra human race”.

“The question is not “when will it become acceptable” but “when will we integrate”.”

“We are able to have so many colours on our sexual pallet now; I think we’d be daft not explore them.”

Questions that will face regulators involve how much data to allow robots to collect about their human partners and send back to their manufacturers.

Others include whether to legislate for purely passive robots, or to allow devices which entice humans to have sex, and whether robots would have to make clear that they are machines rather than humans.

Kate Devlin, computing expert at Goldsmiths, University of London, said it was probable future sex robots would be designed to learn their human partner’s sexual preferences to improve performance.

“Companion” devices such as the Pepper robot are being increasingly used to provide stimulation to elderly people, particularly in Asian countries such as Japan.