Particle on Caithness beach among most radioactive

A rogue radioactive particle linked to the Dounreay nuclear power plant and found on a nearby beach is the "hottest" to be detected since 2008.

The particle was picked up during monitoring of Sandside beach at Reay in Caithness.

It contained 270,000 becquerels of radiation and was in the same category as one found in March 2008.

The most active found so far was a particle recovered in 2007 with a reading of 500,000 Bq.

The particles of Caesium 137 are filings from nuclear fuel rods reprocessed at Dounreay during the 1960s and 1970s.

Flushed into the sea through the plant's liquid discharge pipe, they have been turning up on local beaches for nearly three decades.