The drawing from 1495, held in an archive in Berlin, has never been investigated by a Da Vinci scholar, Hewitt told the Observer. According to the author, the comic is an example of how Da Vinci was being ridiculed by other artists in renaissance Milan.

The drawing shows Da Vinci as a red haired clerk sitting behind a desk, who is looking in an absent-minded way to a half-naked men. He appears to be writing on the table cloth, rather than on his sketch notebooks in front of him. Behind Da Vinci, his father is brandishing a sheet of paper “that surely represents the anonymous document denouncing Leonardo for sodomy”. The bare-chested man in front of Da Vinci is holding an object, that is supposed to represent a contraption made by the artist himself.

Hewitt writes his analysis of the drawing, that was made by Gaspare Visconti, in his soon to be published book Leonardo da Vinci and the Book of Doom.

Da Vinci’s sexuality has always been a topic for speculation and rumours. He was accused of sodomy in 1476, but the charges against him and three others were dropped due to a lack of evidence.