Wave is seen in front of cranes and chimneys of Tokyo Electric Power Co's (TEPCO) tsunami-crippled Fukushima Daiichi nuclear power plant at an area devastated by the March 11, 2011 earthquake and tsunami in Namie town, Fukushima prefecture, Japan May 19, 2018. Picture taken May 19, 2018. REUTERS/Toru Hanai

TOKYO (Reuters) - Japan must act urgently to protect tens of thousands of workers laboring to clean up the damaged Fukushima Daiichi nuclear power station from reported exploitation and exposure to radiation, U.N. human rights experts said on Thursday.

Tokyo Electric Power Co Holdings (Tepco), which owns the nuclear power station that was struck by a tsunami in 2011 that set off meltdowns, has been widely criticized for its treatment of workers and its handling of the cleanup, which is expected to take decades.

A Reuters investigation in 2013 found widespread labor abuses, including workers who said their pay was skimmed and spoke of scant scrutiny of working conditions. Tepco said at the time it was taking steps to limit worker abuses.

Three U.N. experts, who report to the U.N. Human Rights Council, said in a statement released in Geneva that exposure to radiation remained a major hazard for workers trying to clean up the plant, and workers were in danger of exploitation.

“Workers hired to decontaminate Fukushima reportedly include migrant workers, asylum seekers and people who are homeless,” said the three: Baskut Tuncak, an expert on hazardous substances, Dainius Puras, an expert on health, and Urmila Bhoola, an expert on contemporary slavery.

“We are deeply concerned about possible exploitation 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,” they said.

A spokesman for Tepco and a foreign ministry official said they were unable to immediately comment on the statement.

The U.N. rights experts have been engaged in a dialogue with the Japanese government since last year, they said, with the government accepting to “follow up” on some recommendations.