A high-tech York firm has been hired exclusively by two African Governments to crack oil smuggling in separate deals worth millions of pounds.

Kenya and Uganda have demanded that oil companies use the services of Biocode in Dunnington Business Park, York in order to claw back millions of dollars of oil revenue lost to the cheats through illegal fuel dumping and adulteration of fuel products, usually with kerosene.

The Tanzanian Government is now also considering permanently using Biocode's edge-of-science techniques to catch and deter oil criminals.

Biocode, which specialises in anti-counterfeit and product authentication technology, has found the key to combating illegal fuel dumping and adulteration of fuel products by mimicking the chemistry of life to create testing kits for invisible product marking.

In other words, by preparing antibodies which recognise only certain key molecules, it apes the process by which humans respond to germs.

In this case its inspectors' detection tests can establish within five minutes whether markers added to the fuel at distribution depots are present or have been diluted.

The latest contracts, which give Biocode about one per cent of whatever it saves the governments and oil companies, follow its detailed and hugely successful pilot trials in Kenya and Uganda.

Tax accounts for some 40 per cent of the pump price of gasoline and about 30 per cent of the pump price of diesel in Kenya. But when fuel is exported without tax it is considerably cheaper.

This leads to the problem of "tax free" fuel designated for export being dumped illegally back into Kenya.

But by marking all zero-taxed exported fuel in Kenya since October, 1998 early results showed that ten per cent of petrol stations, mostly near the Ugandan border, were receiving illegal fuel.

And by deterring the crooks, the Kenyan Revenue Authority was able to recover $30 million and the oil companies re-claimed about $50 million in sales over the course of the year. A similar exercise in Uganda, where fuel was illegally entering the country, probably from Kenya, yielded total savings of $25 million for the Ugandan taxmen and $15 million sales by the oil companies.

Dr Tim Wilkinson, international director and one of its founders 11 years ago, said that numerous counterfeit prevention deals in the pharmaceutical, wines and spirits and cosmetics industries as well as use of markers in the water industry, had resulted in a turnover of $4.5 million (£3.29 million).

These African and other contracts, however, were likely under the firms chief executive John Davies, to increase year-on-year turnover by between 40 per cent and 60 per cent "but who knows where it will lead us after the first five or six years when the proof of what can be achieved will be demonstrable''.

He said: "We are the only company which can demonstrate real live case studies from concept to completion. We began as a technology company sinking vast resources into research. Now the emphasis is on marketing. Companies and governments don't want to buy technology. They want to be steered to solutions. If your radio is broken you don't want to discuss transistors with the repair man."

Dr Wilkinson was managing director when the firm staged a buyout from Shell Ventures UK in 1992, operating from temporary buildings on the campus of University of York. He was one of the original biology graduates from the University.

The firm, which now employs 25 people, moved to larger premises on the Chessingham Park Industrial estate last December.