OSAKA — Police on Monday sent the cases of two men suspected of selling forged postage stamps to businesses, including voucher shops, to prosecutors.

The case, involving 100,000 counterfeit stamps, is the largest on record.

The two were named as 65-year-old Masaaki Oda, a vendor of garden stone, on trial for charges which include alleged violations of the Mail Law, and 59-year-old Toshio Cho, a self-employed South Korean national who also has the Korean name of Chang Inam. Both reside in the Shikoku region.

A Taipei-based counterfeiting ring apparently mass-produced the forged postage stamps in 1995 in denominations of 80 yen, 100 yen, 300 yen and 400 yen, according to police.

The fake stamps could be distinguished by the quality of the paper and details in the images, they said.

Of the estimated 100,000 fake stamps, worth 20 million yen, some 70,000 are in circulation, mainly among voucher shops. Fake stamps have been found in six prefectures, including Tokyo and Osaka, they said.

Mail bearing the bogus stamps has been cleared by the postal system despite a ministry-issued alert to Japanese post offices.

According to investigations, Cho allegedly received about 77,000 fake stamps worth about 1.4 million yen from Oda in late February 1999 in Neyagawa, Osaka Prefecture.

Postal authorities sent Cho’s papers to prosecutors after he passed the stamps on to an acquaintance in March and April 1999.

Cho allegedly received Oda’s stamps as security for money he had lent him, authorities said.