Last year, Republican congressman Harold Rogers had a provision passed that ensured a trade group called the American Association of Airport Executives (AAAE), its affiliate body, the Transportation Security Clearinghouse, would be hired by the Department of Homeland Security to oversee contracts that could ultimately be worth millions of dollars.

The association said last week it has formed an "operational" partnership with Daon, which last year co-sponsored an airport security conference and a golf outing in Ireland organised by the AAAE. The event was attended by Rogers, who has received financial support from the organisation, as well as attending its AGMs in Hawaii and California.

Critics have questioned how an organisation with uncertain experience in biometrics could undertake assessment of related contracts, and other firms that may have bid for the position have been angered by the move.

In 2004, Daon was part of a consortium that won a $2.5m contract to test a passenger screening system at US airports. The company is unlimited so its accounts are unavailable.

Daon won its first major Irish deal earlier this year when it signed a contract with the Department of Justice, Equality & Law Reform for a scheme to help track immigrants who come to Ireland.

Desmond also used the company's fingerprint recognition technology at his 5m Dublin casino, the Sporting Emporium, which opened last year.

Ridge, who was the first head of Homeland Security, retired early in 2005. He recommended that the US should issue passports that carry the owner's fingerprints, a move he believed would persuade other countries to do the same.

Before he stepped down, it emerged Ridge had spent time at the home of the owner of a lobbying firm that was seeking federal contracts with Homeland Security.