He told the Cheltenham Science Festival that robot technology risked being hijacked for malign purposes in the way the internet has been for pornography unless governments take action.

The former advisor to the United Nations on robotics said he knew of at least 14 companies in South Korea and Japan that were manufacturing and marketing “childcare” robots, and he warned that the growing capability of so-called sex robots means they are likely to enter mainstream use within years.

Devices such as the Roxxxy or Rocky True Companion, which come with an optional “talking” feature, can currently be bought online for around £7,000.

The cost of sex robots is expected to come down, however, as more manufacturers enter the market.