The event has been labelled as "historic" by the organisers, who claim no computer has passed the test before.

"Some will claim that the Test has already been passed," said Kevin Warwick, a visiting professor at the University of Reading and deputy vice-chancellor for research at Coventry University.

"The words Turing test have been applied to similar competitions around the world. However, this event involved the most simultaneous comparison tests than ever before, was independently verified and, crucially, the conversations were unrestricted.

"A true Turing test does not set the questions or topics prior to the conversations. We are therefore proud to declare that Alan Turing's test was passed for the first time on Saturday."

Prof Noel Sharkey, a leading expert in robotic technology and artificial intelligence, said: "It is indeed a great achievement for Eugene. It was very clever ruse to pretend to be a 13-year-old Ukranian boy, which would constrain the conversation. But these competitions are really great to push developments."

But others have criticised the claim.

"It's nonsense," Prof Stevan Harnad told the Guardian newspaper, external. "We have not passed the Turing test. We are not even close."

Hugh Loebner, creator of another Turing Test competition, has also criticised the University of Reading's experiment for only lasting five minutes.

"That's scarcely very penetrating," he told the Huffington Post, external, noting that Eugene had previously been ranked behind seven other systems in his own 25-minute long Loebner Prize test.