A number of forged Japanese-style art prints by late master painters were found to be in circulation following a discovery that an art dealer in western Japan had sold 10 counterfeits, people familiar with the matter said Monday.

The Contemporary Graphic Art Dealers Association of Japan said the dealer, in his 50s and based in Osaka, had sold 10 forged works based on the artists of Nihonga, or traditional Japanese-style arts -- Ikuo Hirayama, Kaii Higashiyama and Tamako Kataoka.

Photo shows a painting drawn by late master painter of Nihonga, or traditional Japanese-style arts, Ikuo Hirayama, in Nara Prefecture on Dec. 2, 2009. (Kyodo)

The dealer has admitted to selling the fake works to the association and was dismissed from the group in December. In the same month, police confiscated what appeared to be fake paintings related to the allegations, according to investigative sources.

The association started investigating after a staff member noticed an unusually high number of works by Hirayama was in circulation last spring.

The counterfeits were elaborate enough to deceive many, except for specialists. With the signatures and the coloring slightly unnatural, the works were revealed as forgeries when they were compared to original works stored in art museums, it said.

Also Monday, Japanese department store operator Sogo & Seibu Co. said that a total of 71 art prints it sold between 2009 and 2020 with sales amounting to around 55 million yen ($520,000) are suspected to be fake.

Since receiving the report on Dec. 1, the retailer has identified customers of 59 out of the 71 pieces and plans on fully refunding those who have purchased any prints that have been appraised and determined to be fake by a third party.

Police are investigating the case as copyright infringement.