Outflanked by criminals who have diversified, police have felt the need to call on investigators from other authorities The increased use of such tactics has alarmed civil libertarians who feel that the risk of infringement of human rights is a high price to pay for any reduction in levels of crime.
But by ditching the traditional rivalries that have dogged relations between police, customs and tax investigators, law enforcement agencies have made considerable inroads in the battle against organised crime.
Alcohol smugglers have been caught driving unroadworthy vehicles. Businesses that employ illegal immigrants have been found to be fiddling their taxes. Suspected terrorists have turned out to be benefit cheats.
But the success of such an exercise depends largely on the effectiveness of the dragnet used to bring the multi-agency investigators into contact with the public. The most popular method, the police road block, has long been a sensitive issue with civil libertarians. Since the criticism of police efforts to obstruct miners' movements during the 1984-85 strike, chief constables have been wary of overusing road blocks. But the success of police operations to tackle drink driving has helped pave the way for greater use of powers to stop motorists.
Chief constables now feel confident to press the Government for greater powers to carry out what would effectively be random breath-testing. The Department of Transport, Environment and the Regions, is expected to support such powers, which could see operations being mounted to test drivers outside pub car parks.
After the IRA bombing campaign in the City of London, police mounted a series of road blocks to restrict the movement of suspect vehicles - the Ring of Steel. The police recently indicated that it intended to continue with the Ring, not because of the renewed threat of bombing, but because the road checks had been successful in detecting other criminals.
When conducting road safety checks, police have become aware of other forms of criminal activity. As a result they have invited other agencies to be present, including Customs & Excise, the Vehicles Inspectorate, Benefits Agency, the Health & Safety Executive, the Driver & Vehicle Licensing Agency, trading standards, the Contributions Agency, the Immigration Service, and the Environment Agency.
Liberty, the human rights group, is planning a legal challenge to the multi-agency questioning. Meanwhile other authorities are embracing the tactics. When the immigration service mounted an operation at Alton Towers leisure park it was accompanied by police and investigators from the Department of Social Security. Customs officers have realised that many contraband smugglers rely on unemployed workers and ageing vehicles. Benefit agency investigators and the Vehicles inspectorate have been used to enforce even greater penalties.