AUTHORITIES on both sides of the Atlantic are working together in an unprecedented move to have Scottish crime lords barred from entering the US, even if they do not have a criminal record.

A Scottish underworld figure and his associates were turned back recently at US immigration after a tip-off from Scottish police.

Officially on legitimate business, the individuals were the first from Scotland to face such sanctions as police in both countries share more information about crime threats.

However, it is understood that Scottish law enforcement - which has pioneered other controversial but effective "disruption" techniques against gangsters and their front companies - will now pursue similar international tactics against other suspects.

One of Scotland's most senior prosecutors approved the decision to pass on intelligence to US authorities.

Lindsey Miller, head of the Serious and Organised Crime Division at the Crown Office, said: "It is up to the Americans who to let in to their country."

Of those stopped at immigration, she said: "They had no previous convictions at all. But the Americans took the decision 'we are not letting you in'."

Asked how they responded, she said: "I understand that they were not best pleased. Travelling to the US - even if you are doing it on a budget - is not cheap. And they were not on a budget."

US authorities can refuse entry to visitors they believe are undesirable, regardless of whether they have convictions. Earlier this month celebrity chef Nigella Lawson was not allowed on to a London jet to the US after she admitted drug use in a civil court case. Ms Lawson has not been prosecuted.

Ms Miller's Serious and Organised Crime Division focuses on efforts to disrupt and dismantle the most serious 20% of organised crime groups.

Her job is not only to convict such people but to make it harder for them to operate. Police and prosecutors increasingly try to damage organised criminals using civil court and administrative measures - where the burden of proof is lower than the "beyond reasonable doubt" of criminal courts.

This includes seizing unearned cash and assets from suspected organised criminals using civil recovery proceedings under the Proceeds of Crime Act. But it also means passing on intelligence about suspected organised criminals.

Police have signed information- sharing protocols with public sector bodies such as watchdogs for charities, lawyers, security firms or MOT garages.

Such authorities can then act, on the balance of probabilities, against the front organisations or individuals of organised crimes.

Police have similar protocols with local authorities and health boards, trying to keep gangland-controlled firms away from state contracts.

And they have revealed details of criminal backgrounds to insurance companies, raising the life insurance premiums of those most likely to meet a violent underworld death.

Some human rights lawyers have argued that such sanctions are unfair - and that suspected organised criminals should have the same rights to a fair criminal trial as anybody else.

However, Ms Miller said: "This was a law enforcement issue, sharing information between police here and in America. If it was not going to affect prosecution strategy, I was happy with it. I would have no difficulty if it was to happen again."

Detective Chief Inspector Paul Donaldson, of Police Scotland's Specialist Crime Division, said: "The individual referred to is part of an investigation which has been reported to the Serious Organised Crime Division. Police Scotland will use all available tactics to disrupt the activities of those involved in serious organised crime.

"The successful use of such disruption tactics will often require the sharing of intelligence and information between partner law enforcement agencies within the UK and beyond."