A Canadian professor's pornography study was ruined after he failed to find any men who had not watched porn.

Researchers at the University of Montreal had planned to create two groups of men in their twenties, with one group made up of regular porn-watchers and the other who had never viewed hardcore films, reports The Sun.

"The objective of my work is to observe the impact of pornography on the sexuality of men, and how it shapes their perception of men and women," said Professor Simon Louis Lajeunesse.

However, he was stunned when he failed to find men who had never watched explicit films.

"We started our research seeking men in their twenties who had never consumed pornography but we couldn't find any."

Rather than completely abandon the study, they instead altered it to examine at the habits of men who do use pornography.

According to their results, on average, young single men view porn for 40 minutes, three times a week, while men in committed relationships watch for for 20 minutes, 1.7 times a week.