A stretch of Aberdeen beach has been closed to the public after traces of radioactive material were found in the sand.
The radioactive material was found during routine monitoring
The particles were found below the tide level during routine monitoring of the beach in late July.
A 100-yard stretch of the beach has been cordoned off while the Scottish Environment Protection Agency (Sepa) carries out an investigation.
NHS Grampian said the amount found poses a negligible risk to the public.
Sepa said it had found higher than normal levels of radioactivity in a small area of sand at the southern end of the beach, near the harbour wall.
It is understood the radioactive substance is naturally occurring, but not normally found in that type of location in such a concentration.
It is also found on offshore oil drilling equipment used in North Sea operations.
A wider area of the beach will be monitored over the next few days to confirm the extent of the contamination.
Production at environmental services company, Scotoil Services, has been halted as a precaution.
A spokesman said: "We are obviously very concerned about this, but it is important to state that at this stage no link has been established between the finding of this material and the Scotoil Services operation.
"However, as a precaution we have suspended operations. We shall, of course, be co-operating fully with Sepa and other authorities in their investigations.
"We continue to have confidence in our procedures, which have been continuously reviewed and closely monitored now for more than 20 years.
"During this time there have been no issues reported."
Scotoil Services has provided descaling, decontamination and disposal services for the oil and gas industry since 1983 and is based near Aberdeen harbour.