A new study has found that the "cuddle" hormone oxytocin can rival Viagra in improving a man's sexual performance.

Oxytocin is a "feel-good" hormone that is released into the bloodstream after sex in both men and women, and is also released in women during labour, triggering the production of breast milk and encouraging mothers to bond with their babies.

In the study, which was published in the Journal of Sexual Medicine, researchers followed a subject who had attention deficit disorder, had difficulty maintaining social relationships and was experiencing relationship issues with his wife. The subject was required to use a nasal spray containing the chemical twice a day.

Findings showed that the married father of three reported a significant improvement of performance in the bedroom.

His libido went from "very weak" to "somewhat strong", his  sexual arousal went from "somewhat difficult" to "somewhat easy" and the act itself was easier to perform and more satisfying.

Not only did the spray improve his sexual prowess, but the subject also displayed more affection towards his wife.

All benefits stopped when the subject discontinued using the nasal spray.

Researchers in the California study said the developments were 'in keeping' with those of Viagra.

They concluded: 'These findings support trials directly examining the use of oxytocin to treat problems in this vital aspect of human function, especially in the context of stable, loving relationships.'

Dr Mike Wyllie, one of the scientists who developed Viagra, said that a drug based on oxytocin could have "blockbuster potential".