Twenty-seven foreign nationals died in fiscal 2009 after coming to Japan for employment under a government-authorized training program, the second-highest figure on record.
Most of the workers who died were in their 20s to 30s, officials at the Health, Labor and Welfare Ministry said.
Nine died of brain or heart disease, four died while working, three committed suicide, three died in bicycle accidents and the rest died of unknown causes, according to the officials.
The Lawyers' Network for Foreign Trainees plans to demand that the ministry investigate how the trainees died and take steps to prevent recurrences.
"Many trainees who died of brain or heart diseases could have actually died from overwork, while those who killed themselves could have committed suicide induced by overwork," said Shoichi Ibuski, a lawyer and expert on the issue.
By country, 21 were from China, three from Vietnam, two from the Philippines and one from Indonesia.
The toll follows the 35 foreign trainees who died in fiscal 2008. This could trigger moves toward revising the program, launched in 1993, because a number of irregular practices have recently emerged, including having foreign trainees work long hours for less than the minimum wage.
"We are taking the figure seriously. We will thoroughly implement conventional measures and instruct (firms) not to let such incidents happen again," a ministry official said.
On the issue of foreign trainees, a labor office in Ibaraki Prefecture recently decided to recognize the 2008 death of a Chinese intern as "karoshi" (death from overwork).