Hitachi Ltd. and its 10 group firms have been slapped with improvement orders for using foreign trainees illegally, including paying them less than the minimum wage, sources close to the matter said Tuesday.

It is the second time in eight months that Hitachi has come under scrutiny for the way it employs and deploys trainees.

The Organization for Technical Intern Training carried out inspections at 12 plants between April and September last year.

It found technical interns engaged in work outside the remit of their training programs, in violation of a law on the government-sponsored scheme, the sources said.

If the OTIT finds Hitachi firms have not taken sufficient steps to improve the situation, it will report the cases to the justice and labor ministries, and their training programs could be withdrawn.

The technical internship, introduced in 1993 to transfer skills in Japan to developing countries, has faced criticism at home and abroad over perceptions it is used as a cover for companies to import cheap labor.

Many companies in Japan depend on the trainees amid a severe labor crunch in the rapidly aging country, but long working hours and harsh conditions have been reported by recruits.

Hitachi denied having paid the trainees below the minimum wage but did admit receiving an advisory for improvement and instruction from the OTIT.

"We have already implemented improvement measures and reported them to the OTIT," Hitachi's public relations and investor relations office said, while declining to elaborate on the instructions its firms have received.

In July last year, the Justice Ministry and OTIT conducted a joint investigation at Hitachi's Kasado train factory in Yamaguchi Prefecture, western Japan, over allegations it assigned interns to tasks other than those prescribed in their training programs.

Authorities including the Justice Ministry, which supervises the technical intern training program, are considering taking disciplinary action against Hitachi over the Kasado plant case.

At that factory, 99 Philippine trainees were fired last fall after their training programs failed to obtain approval from the Japanese government, preventing the renewal of their visas as technical interns.

In December, the OTIT approved training programs for 26 of them, allowing their reemployment as welding works trainees. For the remaining 73, originally accepted as electric equipment assembly trainees, a decision was yet to be made at that point, and 46 of them returned to the Philippines.