The head of Tokyo Electric Power Co has sent a rare English message to calm fears over the impact of the Fukushima accident, which had overshadowed Tokyo's bid for the 2020 Olympics.

"We deeply apologize for the greater anxiety caused by the accident at Fukushima Daiichi nuclear power station," TEPCO President Naomi Hirose said in a video message posted on its home page.

"Supported by the Japanese government ... all of us at TEPCO will strive relentlessly to control the contaminated water," Hirose said in English.

But he denied any significant impact on the environment outside the plant, playing down fears over the possible spread of radiation.

"We believe that the impact on the surrounding waters is limited to the area within the port of the power plant," he said.

"And that judging by the results of our monitoring three kilometers offshore there has been no impact on the water or the wider ocean," he added.

A TEPCO spokesman said the posting of the message "just coincided" with the final days of the Olympic race.

"We had long prepared for the message as there was a concern in other countries over the leak of contaminated water," the spokesman said. "It's nothing to do with Olympics."

© (C) 2013 AFP