Extra police will be put on the streets during full moons after officers found a link between violent crime and the lunar cycle.

Inspector Andy Parr, of Sussex Police, was investigating external factors which affect people's behaviour when he discovered the link.

He said: "I compared a graph of full moons and a graph of last year's violent crimes and there is a trend."

Full moons and paydays were identified as key days when aggressive behaviour rises among drinkers in central Brighton's nightclubs and pubs.

Now police will respond this summer by putting extra bobbies on the beat on those days.

Insp Parr said: "Even if it is only one extra officer it can help prevent violent crime from taking place."

As well as causing violent crime, drinkers tended to be more aggressive and unhelpful during the full moon.

Insp Parr said: "People tend to be more aggressive generally.

"I would be interested in approaching the universities and seeing if any of their post-graduates would be interested in looking into it further. This could be helpful to us."

Extra police, on a larger scale, are already sent out on bank holidays and when there are large one-off events such as seafront gigs.

Insp Parr helps co-ordinate policing in the city's "marble" area, a police term for streets home to Brighton's busiest pubs and clubs.

It includes West Street, the seafront, East Street, parts of the Pavilion Gardens and extends from St James Street to Bedford Square.

Bouncer Terry Wing said: "It's so true. When there is a full moon out we look at the sky and say, "Oh no, all the idiots will be out tonight."

"I will start looking at the back of people's hands for hair next time."

Mr Wing, who is a former psychiatric nurse, said there was an established link between patients suffering from manic depression and the full moon.

He said: "It was thought the illness was related to the cycles of the moon."

Jim McFruin, the assistant manager of the Black Lion Pub in Black Lion Street, Brighton, said he hadn't noticed the link full moons and aggressive behaviour.

He said: "It's not something I've particularly noticed but I have been told about it before by a friend who used to work with the police.

"Doctors who work in casualty departments have also mentioned it before.

"Whether or not it is linked to alcohol, I don't know."

Taxi driver Damien Norman said: "It's a new one on me. I've been very lucky though and never had too much trouble from members of the public. I haven't noticed any difference with a full moon."

Earlier this year Professor Michal Zimecki of the Polish Academy of Sciences published a scientific paper which argued the full moon could affect criminal activity and health.

Full moons have long been blamed for extremes in human behaviour, including the transformation of men into the mythical beasts known as werewolves.

The word lunatic means, according to the Oxford English Dictionary, "affected with the kind of insanity that was supposed to have recurring periods, depending on changes of the moon."

The lunar cycle is aligned to women's menstrual cycles and the changing of the tides.

In 1992 Dr Peter Perkins, from Bournemouth, found calls to accident and emergency departments went up by three per cent during full moons.

He believes the human body is influenced by gravitational forces from the moon.