The Kenya Wildlife Service (KWS) is seeking royalties from a US biotech company it says illegally acquired the active enzyme ingredients used in detergents and bleaching agents that give denim a stonewashed look.

Genencor International BV of the Netherlands is accused of illegally extracting and clothing the "extremophiles" (tiny organisms that can survive in extreme environmental conditions) from highly caustic lakes in Kenya's Rift Valley.

These were then sold to US multinational Procter & Gamble, which used them as critical ingredients in the manufacture of its Tide Alternative Bleach Detergent.

The KWS has written to lawyers working for Public Interest Intellectual Property Advisors (PIIPA) in the US to handle the matter on its behalf.

Genencor is believed to have made more than $1 million selling its products to textile firms and detergent manufacturers.

KWS says neither Grant nor Genencor had permission to take the organism samples necessary to produce the chemicals.

Genencor denies the charge and says it was given a permit by the Kenyan National Council for Science and Technology.