A Hawaiian affiliate of UCC Ueshima Coffee Co. is suspected of mixing premium Kona coffee beans with cheaper beans and selling the mixture as Kona 100%, according to an accusation document obtained by Kyodo News.

UCC Ueshima, based in Kobe, has denied the allegation, saying an in-house investigation could not confirm any such activity.

Several former employees of the affiliate told Kyodo News that they were involved in the fraud.

The accusation document, issued by Shunichiro Fukada, a former vice president of the affiliate, was sent to the Agriculture, Forestry and Fisheries Ministry as well as industrial organizations.

Between 1989 and 1996, according to Fukada and the former employees, the affiliate mixed Colombian beans -- whose prices were one-fifth those of Kona -- with Kona beans before roasting and grinding.

Most of the Kona 100% was sold at drug stores and souvenir shops in Hawaii, mainly to Japanese tourists, while some was exported to Japan between 1993 and 1995, they said.

Atsushi Kawamoto, a member of the company's board, said, "If the deception really happened, the former vice president did it by himself."

Fukada, who lives in Honolulu, said, "It is unforgivable that UCC is trying to lay the responsibility only on me."

UCC Ueshima is a leading coffee company in Japan with annual sales of 146 billion yen. Established in 1933, it began selling Japan's first canned coffee in 1969.