Three United Nations human rights experts criticized the Japanese government Thursday for allegedly exploiting and putting at risk the lives of "tens of thousands" of people engaged in cleaning up operations at and around the crippled Fukushima nuclear plant.

In a joint statement, the experts expressed their deep concerns "about possible exploitation by deception regarding the risks of exposure to radiation, possible coercion into accepting hazardous working conditions because of economic hardships, and the adequacy of training and protective measures."

"Workers hired to decontaminate Fukushima reportedly include migrant workers, asylum seekers and people who are homeless," the experts said, adding they were "equally concerned about the impact that exposure to radiation may have on their physical and mental health."

The press release called on the Japanese government to urgently "protect tens of thousands of workers who are reportedly being exploited and exposed to toxic nuclear radiation in efforts to clean up the damaged Fukushima Daiichi Nuclear Power Station."

The statement was issued by Baskut Tuncak, special rapporteur on the disposal of hazardous substances and waste, Urmila Bhoola, special rapporteur on contemporary forms of slavery, and Dainius Puras, special rapporteur on physical and mental health.

In Tokyo, an official of the Health, Labor and Welfare Ministry called the statement "regrettable," saying it was based on one-sided information and stressed that the Japanese government has been sincerely dealing with the matter.

"We properly handled problematic cases in the past and do not regard it as a situation which requires any urgent response," the official said.

The Foreign Ministry also expressed disappointment, saying the statement unnecessarily sparks worries and confusion.

"It's regrettable as the statement based on one-sided allegations that could exacerbate the suffering of people in the disaster-hit areas," the ministry said.

There have been cases of payments not being distributed to subcontracted laborers and of workers not being allowed to take necessary health checkups.

Some foreign trainees under the government's Technical Intern Training Program have also engaged in cleanup operations without the nature of the work being properly explained.

Tuncak is expected to present a report to the U.N. Human Rights Council next month aimed at strengthening the protection of workers exposed to toxic substances.