Data compiled by officials and police show that three years after the disaster, 1,656 people living in Fukushima prefecture have died from stress and other illnesses related to the tsunami.

That compares with the 1,607 people who were killed as the huge waves hit the coastline.

Hiroyuki Harada, a Fukushima official dealing with victim assistance, said: "People have gone through dramatic changes of their environment.

"As a result, people who would not have died are dying."

Bags of irradiated soil are dumped in a tennis court in Naraha

Along with the prefectures of Miyagi and Iwate, Fukushima was one of the worst-hit parts of Japan when the powerful earthquake triggered the tsunami.

The waves left more than 18,000 people dead across the country and destroyed entire communities.

The tsunami caused a nuclear disaster after cooling systems at the Daiichi plant were knocked out, sending reactors into meltdown and forcing the evacuation of thousands of people.

Many people remain displaced, with homes around the plant declared unsafe and rebuilding programmes progressing slowly.

Mr Harada said: "This is different from normal natural disasters.

Namie is still off-limits three years after the tsunami and meltdown

"People who live in shelters are forced to live there, away from their home towns and villages, where they lived for a long time.

"They are forced to live the kinds of lives they are not used to."

In Minamisoma, 447 deaths have been indirectly blamed on the disaster. Namie had 317 deaths and Tomioka has 225.

Parts of Minamisoma and all areas of the other two towns are off-limits because of radiation levels.

Scientists say parts of Fukushima may have to be abandoned and much of the area around the plant remains out-of-bounds.

It comes as highly radioactive water was found to have leaked from a storage tank at the crippled power plant.

Operator Tokyo Electric Power Co said on Thursday the leak involved partially treated water, but it did not flow into the Pacific Ocean.

Three reactors at the plant melted down following the tsunami.