At a ceremony at the French national assembly attended by Nobel prize winners, former government ministers, MPs, decorated scientists and academics, all attention was on a previously unknown literature professor.

Florent Montaclair, then 46, a balding, bespectacled figure in an ill-fitting suit and rosé-coloured shirt, was receiving the 2016 Gold Medal of Philology - the study of linguistics – from an international society of the same name.

Montaclair was the first French recipient of the medal, previously awarded to the Italian author and linguist Umberto Eco , those attending were told.

It was a glittering event and an impressive achievement – but unfortunately, detectives claim, the award itself was entirely fake and part of a complex international hoax worthy of a film script.

Although the ceremony did take place, there was no International Society of Philology.…