The government unveiled Tuesday tougher penalties on employers and supervisory bodies for the disappearances of foreign technical interns, with those with records of many missing trainees to be banned from accepting new interns.

The technical internship program has been criticized over the number of trainees who flee their workplaces, with many citing harsh working conditions and bad treatment. Such trainees are basically not allowed to change jobs and are believed to become undocumented workers after quitting the program.

The Immigration Services Agency said even if only a few interns go missing, employers who are found to have engaged in illegal activities such as non-payment of wages will be banned from accepting new interns.

"We'll steadily enforce the measures to decrease the number of those who go missing at any cost," Justice Minister Masako Mori said at a press conference.

The number of disappearing trainees has been on the rise with 9,052 going missing in 2018, up 1,963 from the previous year, according to the agency. The figure in the first half of 2019 stood at 4,499, up 256 from a year earlier.

The state-sponsored training program introduced in 1993 is aimed at transferring skills to developing countries, but the scheme has drawn fire at home and abroad as a cover for importing low-cost labor.

The agency will write to all the supervising bodies to ask for cooperation and conduct more interviews with technical interns to check whether there have been any issues over payment and human rights abuses.

In March, the Justice Ministry said around 15 percent of 5,218 foreign trainees who went missing from work had been unjustly treated by employers, including non-payment and overtime work.