A new group set up to mediate internships for foreign students allegedly skimmed nearly ¥3 million ($28,000) from the wages of a dozen Vietnamese women employed at inns and other lodging facilities in Ishikawa and Fukui prefectures, labor authorities say.

The Japan Asia International Friendship Association, based in Fukui, allegedly siphoned off the money while the university students were employed at ryokan (traditional inns) and other lodging in Ishikawa and Fukui from September 2016 to May 2017.

When the inns deposited the students' wages into the association's bank account, it extracted ¥100 per hour for "administration costs," the Fukui labor office said. The illegal practice netted the group ¥2.96 million, the office said.

On Friday, labor inspection offices in both prefectures handed prosecutors their investigative papers on the Japan Asia International Friendship Association and its head, 30-year-old Toshihide Inoue. It is rare for a case of intern exploitation to be referred to prosecutors, investigative sources said.

Inoue said that the money was used to cover the association's labor costs and other expenses and that he "was not aware it was illegal." He also said the association stopped the practice after it was warned by the labor authorities.

The association was set up in 2016 to promote international exchanges. It has mediated internships at Japanese lodging facilities for foreign students mainly interested in studying Japanese. Completing the six- to 12-month internships allows them to earn credits toward graduation.