A newly study published on Tuesday by the Proceedings of the National Academy of Science confirms what men of average size fear - women are more attracted to males who have large penis.

The study's findings contradict previous studies made by other groups that size does not really matter.

Instead of asking female respondents directly if they are attracted to males with big sex organs, the study which had 105 Australian women as subjects, were asked to view 53 life-sized robot-like photos that were rotated to make the image visible at different angles. The figures had computer-generated images of generic male figures that had different heights, body shapes and penis lengths that were still flaccid.

All of the respondents were heterosexuals and were informed the study was not about penis size, but to rate the images according to sexual attractiveness.

Tall men with long penises were given the most thumbs up by the respondents. On the average, they gazed at the images for about three seconds.

However, while penis size influenced the attractiveness of males, the study found that it was only true when the length of the flaccid penis reached 7.6 centimetres (or 3 inches). Beyond that size, the attractiveness declines, said Brian Mautz from the Australian National University in Acton.

Previous studies indicate that the average penis size when flaccid is about 3-4 inches and when erect 5 to 6 inches.

The study, however, failed to find an ideal or most attractive penis size or height ideal, although the attractive scores increased for men with large sex organ sizes.

"Our results show that female mate choice could have played a role in the evolution of the relatively large human male penis," the authors wrote.

"Before clothing, the non-retractable human penis would have been conspicuous to potential mates ... Our results directly contradict claims that penis size is unimportant to most females," the study said.