SCOTTISH schools and hospitals could be affected by the horse meat scandal, it has emerged.

The Food Standards Agency (FSA) in Scotland said it was working with public institutions in its inquiries.

It came as Tesco announced tests had shown one of its Spaghetti Bolognese ready meals had been contaminated, with some of the products tested found to be 60% horse.

There were also reports donkey meat may be entering the food chain, while a charity said it was investigating an estimated 60,000 missing horses on either side of the Irish border.

Scottish Government ministers have met with the food watchdog and the industry to discuss the escalating crisis.

Charles Milne, director of the FSA in Scotland, said it was important the public had clear and accurate information" about the food they buy and eat.

He said it was particularly important public institutions serving food to some of the most vulnerable were included in discussions.

He added: "While there is no evidence to suggest there is a risk to public health, the FSA has ensured businesses supplying public institutions with meat products are included in actions under way in Scotland and across the UK more widely."

Inspections are being carried out in all approved meat processing facilities in Scotland.

Michael Matheson, the Public Health Minister, said: "Food businesses supplying processed beef products to public-sector premises, including schools, prisons and hospitals, are already involved in an inspection and testing regime led by the Food Standards Agency.

"I am reassured the FSA is working closely with our suppliers and caterers, and I would reiterate there continues to be no evidence of any implications for human health at this time."

It comes as Tesco announced its frozen Everyday Value Spaghetti Bolognese was the latest product found to be contaminated with horse DNA.

Some of the products were almost two-thirds horse meat.

Tesco said the meal had been made by Comigel, the French food firm which made the Findus lasagnes found to contain up to 100% horsemeat last week, and said it was dropping the firm.

Tesco's technical director, Tim Smith, said the store withdrew the product a week ago as a precaution. He said: "We have carried out a number of tests and those tests identified the presence of horse DNA."

He said most of those tested showed trace levels of less than 1% but three had much more significant levels of horse DNA.

Mr Smith said the product should only have contained Irish beef from approved suppliers and the source was under investigation. He also apologised. He added that the tests proved clear for phenylbutazone, known as bute, the horse drug banned from entering the food chain.

Despite fears over the anti-inflammatory, officials said there was little risk to humans.

Environment Secretary Owen Paterson faced angry scenes when he told MPs that those who were ultimately responsible for food security was the retailers.

Shadow Environment Secretary Mary Creagh told Mr Paterson the lack of information from the UK Government had been a disgrace.

The Ulster Society for the Prevention of Cruelty to Animals (USPCA) said there were currently thousands of horses unaccounted for in Northern Ireland.