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Fukushima radioactive water leak an 'emergency'

6 August 2013 Last updated at 07:44 BST

Japan's nuclear watchdog has said the crippled Fukushima nuclear plant is facing a new "emergency" caused by a build-up of radioactive groundwater.

A barrier built to contain the water has already been breached, the Nuclear Regulatory Authority warned.

This means the amount of contaminated water seeping into the Pacific Ocean could accelerate rapidly, it said.

Rupert Wingfield-Hayes reports.