Japan minister at Fukushima after radioactive leak

This hand out picture taken by Tokyo Electric Power Co (TEPCO) on August 19, 2013 shows contaminated water which leaked from a water tank at TEPCO's Fukushima dai-ichi nuclear power plant.

TOKYO - Japan's government was ramping up pressure on electric utility TEPCO after a huge leak of radioactive water at Fukushima, with a planned ministerial visit to the wrecked nuclear site Monday.

The visit by Toshimitsu Motegi, whose ministry supervises the atomic energy industry, comes amid growing calls for the government to take a greater role in the clean-up at the plant.

Critics accuse TEPCO of being incapable of dealing with the huge - and growing - volumes of radioactive water at the site.

Motegi arrived at the "Fukushima Revitalisation" local office of Tokyo Electric Power Co (TEPCO), some 20 kilometres (12 miles) from the broken plant.

He was to move to the plant later in the day, a TEPCO official said, adding that he will then hold a news conference.

His second visit to the plant - the first was in January - comes after TEPCO revealed around 300 tonnes of highly radioactive water escaped from one of the hundreds of tanks storing liquid used to cool the broken reactors.

The episode was dubbed the most serious since the plant went into meltdown in 2011 after being hit by a quake and tsunami.

Prime Minister Shinzo Abe in early August described as "urgent" the battle to stop contaminated water from escaping into the ocean.

Inspectors from Japan's nuclear watchdog who toured the plant Friday declared water storage at the site was "sloppy".

TEPCO said Saturday the tank that sprang a leak was one of three to have been relocated from its original spot because of subsidence.

The utility has not yet pinpointed the reason for the problem with the first tank but at the weekend began emptying the other tanks that were moved with it in 2011.

On Sunday, Japanese Foreign Minister Fumio Kishida visited Chernobyl in Ukraine, the site of a 1986 nuclear disaster, and was due to hold talks with his Ukrainian counterpart on Monday.

Kishida went on his fact-finding mission to Chernobyl with the aim of sharing experience in overcoming the consequences of nuclear disasters, a spokesperson said.