British startup Spinvox has been accused by the BBC of running vast call centre operations across the world to turn voice into text, rather than the AI system that the company claims that it uses on the website.

The company says that its software is "a combination of artificial intelligence, voice recognition and natural linguistics", whereas the BBC quotes a former employee, who says he worked in a call centre, as saying "It was done 100% by people".

Questions have been raised over the privacy of the messages sent through Spinvox, as well as its compliance with data protection legislation. The company's entry on the UK Data Protection Register says it doesn't transfer anything outside of Europe.

The BBC's tech correspondent, Rory Cellan-Jones, says he recorded a message and then played it through identically 5 times through the service. You'd expect a computer to return 5 identical versions, but instead several different variants arrived back.

Spinvox hasn't, at the time of writing, responded to the allegations.

Update: Spinvox's CEO, Christina Domecq, has responded, telling the Guardian: "We seem to be under sustained attack by some former employees. The ratio of humans to messages and humans to number of users is very, very low. The majority of calls are fully automated".