The Radioactive Waste Management Advisory Committee has insisted that Sandside Beach in Caithness is safe for public use.

The source of the contamination is linked to the Dounreay nuclear plant nearby and - despite predicting that more fragments will turn up - Rawmac said they pose no major risk.

In its annual report, the watchdog praised Dounreay management's progress in trying to track the source of the hot-spots but said the monitoring of local public beaches must continue.

Five particles have been detected on Sandside Beach, including two in the past month, and there is pressure from anti-nuclear campaigners and others to close it.

Operators were praised for their efforts in tracing particles

But Rawmac's Professor Keith Body said it has been estimated the chances of encountering or ingesting a particle the size of a grain of sand is one in a thousand million.

He maintained the levels of activity in each grain pose little risk to health.

Prof Body was adamant the beach should stay open, maintaining he would let his own grandchildren play on it.

The operators of the Dounreay nuclear plant recently denied delaying an announcement of a radioactive hot-spot find at Sandside Beach.

But environmental campaigners Friends of the Earth said the operators waited two days before revealing the find.

It prompted the Scottish National Party to condemn what it called Dounreay's "appalling record of secrecy and cover-up".