The BBC has rewritten Poirot's history, as the finale of its divisive adaptation revealed the detective was a priest.

The episode, aired last night, jettisoned another piece of the Agatha Christie canon when it wrote out the character’s traditional former profession as a policeman.

The backstory of the BBC's private detective, played by John Malkovich, instead revealed he trained as a priest only to relinquish his vows after deciding that incarcerating serial killers was his true calling.

It comes as the BBC’s version of the The ABC Murders has already angered some Poirot fans by dispensing with iconic elements of the character.

Malkovich's iteration has ditched the detective’s trademark Belgian accent and replaced his upturned mustache with a goatee beard.

The three-part series was written by Sarah Phelps, who has previously adapted three other Agatha Christie books for the BBC.

Phelps earlier revealed that she had never read or watched a Poirot story before working on the screenplay and that she relied exclusively on 1936 the ABC Murders novels while constructing her character.

Many of Poirot’s most famous features originate from other Christie novels in which he appears. For instance his “upward-curled moustache” was first described in Murder on the Orient Express.