ASECTION of beach about 100 yards long was sealed off in Aberdeen yesterday after the area was found to be contaminated with radioactive material.

Environment watchdogs launched an investigation after the discovery.

The Scottish Environment Protection Agency (Sepa) reported that 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.

The radioactive substance is understood to be naturally occurring, but not normally at this level of concentration in such a location. The substance is also found on offshore oil drilling equipment used in North Sea operations.

Sepa said the risk to the public was likely to be "negligible".

The organisation will monitor a wider area of the beach during the next few days to confirm the extent of the contamination.

Tidal movement will also be studied as Sepa investigates the source of the material.

A spokesman for Aberdeen City Council said that a small part of the beach would be closed to allow Sepa to conduct its investigation.

Production at a locally-based environmental services company was also halted yesterday as a precaution.

Scotoil Services was contacted in the afternoon about the substance.

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 cooperating fully with Sepa and other authorities in their investigations."

The spokesman added: "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 provides descaling, decontamination and disposal services for the oil and gas industry.