Japan's Fukushima Daiichi nuclear plant is under the spotlight once again.

Tepco, which runs the plant, is still dealing with damage from the earthquake and tsunami of 2011.

Now they say groundwater radiation levels have risen significantly in the last week.

The soaring radiation levels suggest highly toxic materials from the plant are now close to the Pacific Ocean.

Tepco has been flushing water over its reactors to keep them cool for more than two years, but contaminated water is building up at the rate of an Olympic-size swimming pool per week.

In April, Tepco sought approval to channel what it has described as 'groundwater with low levels of radiation' around the plant and to the sea.

Local fishermen oppose the proposal.