A POLICE intelligence cell has uncovered evidence that hardcore Scottish football hooligans are intent on causing trouble at the World Cup.

Their number is described as ''small,'' and officers remain confident that the impeccable behaviour of Scottish fans in recent years will be upheld in France.

According to police sources, information gathered by the top security, Paisley-based intelligence unit suggests the number of potential Scottish troublemakers will be lower than the 150 identified prior to soccer's European Championships in England in 1996.

It is understood that suspects will be approached informally by Scottish officers when on French soil. The tactic is aimed at tempering their behaviour because they will know they have been identified. It is also understood they will be pointed out to French police, who will decide if extra surveillance is necessary.

The Scottish intelligence unit was established several months ago, and has already passed on information to the French authorities via National Criminal Intelligence headquarters in London.

Mr Peter Gibson, Strathclyde's Assistant Chief Constable (Operations), confirmed yesterday that Scotland's eight police forces ''are aware that there is a small number of people that may attempt to use the World Cup as a platform to cause trouble.''

He will be the direct liaison officer to French police at Scotland's opening round matches in Paris, Bordeaux and St Etienne under a scheme designed to ensure Scots fans contribute to carnival atmospheres rather than damage them.

Scottish officers will be in stadium control rooms as well providing ''spotters'' on a roving commission with French police to identify known trouble-makers. The spotters will also offer guidance to the authorities on typical Scottish boisterous behaviour, deemed harmless rather than criminal.

Fans have been warned they face prison sentences within 48 hours of arrest under a fast-track judicial system introduced for the tournament.

Mr Gibson said yesterday: ''I am optimistic that the behaviour of Scottish fans will be a repeat of the excellent record they hold over past campaigns.

''The French authorities witnessed the fervour displayed by Scottish fans on their visit to Scotland this year and, if anything, they are looking forward to the Scots contributing to the festival atmosphere in their own inimitable way.''

However, he cautioned fans against buying tickets on the black market because they face being turned away at stadiums if their validity was challenged.

Mr Gibson warned: ''Scots supporters should expect to face a series of checks when they approach the stadium by both police officers and stewards.

''At every venue there will be several ticket checks . . . as supporters draw nearer to the stadium, they should expect to undergo random searches before a close ticket inspection prior to entry.''

His comments on tickets coincided with a warning from Edinburgh City Council not to buy briefs from a Dutch company who advertised in Scotland last month.

An investigation by the council's consumer services department and Dutch fraud squad suggests only unauthorised tickets will materialise.