A case of BSE, or so-called mad cow disease, has been identified at an Aberdeenshire farm a decade since it was last confirmed in Scotland.

Restrictions have been put in place at the unnamed farm as investigators try to establish the source of the fatal disease, known in full as Bovine Spongiform Encephalopathy.

The case was identified as part of the routine testing of all animals over four years of age that die on farms.

It did not enter the food chain and there is no risk to human health, officials said. The farmer is co-operating and is receiving support.

Scotland's Chief Veterinary Officer Sheila Voas said: "While it is too early to tell where the disease came from in this case, its detection is proof that our surveillance system is doing its job.

"We are working closely with the Animal and Plant Health Agency to answer this question, and in the meantime, I would urge any farmer who has concerns to immediately seek veterinary advice."

A precautionary movement ban has meanwhile been placed on the farm.

Fergus Ewing, Scotland's Rural Economy Secretary, said he had activated a government response plan to protect Scotland's farming industry.

He said: "While it is important to stress that this is standard procedure until we have a clear understanding of the disease's origin, this is further proof that our surveillance system for detecting this type of disease is working."

Millions of cattle were culled in the UK in the 1990s during a BSE epidemic.

It can be passed on to humans in the food chain, causing a fatal condition called variant Creutzfeldt-Jakob disease (vCJD).

Strict controls were introduced to protect consumers after the link was established in 1996.

The disease has been reduced to a handful of cases each year in the UK, with the last recorded case in Wales in 2015.

Scotland has been BSE free since 2009.

Ian McWatt, director of operations at Food Standards Scotland, said: "There are strict controls in place to protect consumers from the risk of BSE, including controls on animal feed, and removal of the parts of cattle most likely to carry BSE infectivity.

"Consumers can be reassured that these important protection measures remain in place and that Food Standards Scotland official veterinarians and meat hygiene inspectors working in all abattoirs in Scotland will continue to ensure that in respect of BSE controls, the safety of consumers remains a priority."