A bankrupt temporary staff service firm has failed to pay about 120 million yen in wages to some 320 foreign workers at its branch in Isawa, Yamanashi Prefecture, a labor ministry office said Friday.

The Kofu Labor Standards Inspection Office in Yamanashi Prefecture said foreign workers at Toyo Gijutsu Kogyo's other branches in and around the Kanto region have also not been paid.

The firm, based in Suginami Ward, Tokyo, collapsed in late March, leaving some 1.2 billion yen in liabilities, according to corporate credit researchers.

The labor ministry office said it is currently investigating the case in cooperation with the Shinjuku Labor Standards Inspection Office in Tokyo, which supervises Toyo Gijutsu's headquarters.

Toyo Gijutsu concluded contracts with dozens of companies in Yamanashi Prefecture and dispatched Japanese-Brazilian and Japanese-Peruvian workers to their factories.

The Kofu Labor Standards Inspection Office learned that Toyo Gijutsu did not pay the workers' wages in February and March. It began receiving complaints from workers in late February.

Toyo Gijutsu told the inspection office that although it is willing to pay the wages, it lacks the funds, according to the office.

The company's Isawa branch closed in late March without informing its workers. That office and the firm's Tokyo headquarters could not be contacted since then.