Two offenders have been hit with lifetime bans while another 70 have received orders covering up to two years.

Those banned – mostly aged between 18 and 26 – have typically been caught fighting or in possession of drugs.

Pictures of the clubbers have now been circulated around all door staff in the city to ensure they stick to the ban.

Police today said the move, part of the Unight scheme established five months ago, had already led to a fall in late-night disorder.

Pc Mark Pickavance, who helped set up the scheme, said: "It is proving very successful and that is shown in the falling crime figures.

"Now word is getting out and people realise that they face not only charges from police, but bans from going to clubs.

"Peer pressure from friends is stopping them from offending because they don't want to get left out on Friday and Saturdays."

A total of 38 late-licence premises have signed up to Unight and the final remaining two are expected to join this week.

Of the 72 people banned, two were for life, 18 for between one and two years, and 52 for between three and six months.

The majority of drug seizures resulting in bans were for cocaine, with ecstasy also figuring highly.

Bouncers who detain culprits still call police to investigate, but those banned also have their images added to a book kept by all Unight members.

Under the data-sharing system, still pictures of drug-takers or violent customers taken from CCTV cameras are sent to other clubs.

Offenders are given a banning letter prohibiting them from entering any of the venues.

Sarah David, owner of Cabaret Voltaire in Blair Street and chairwoman of Unight, lauded the new scheme. She said: "Cabaret Voltaire was already a club with very few incidents because of our door policies, but Unight has helped us further.

"I think the severity of the punishment is having an effect. Previously, someone banned from one venue simply moved on to the next and this would continue."

Police recorded 46 drug offences, 12 thefts and three assaults at the Blair Street premises between November 2006 and February last year. Those figures fell to just one drug offence, seven thefts and two assaults between November last year and February after Unight was launched.

Don Webley, 26, became the first person to receive a life ban earlier this year after being jailed for ten months for a vicious assault outside City in Market Street.