Thieves made off with 19 Red Poll cattle, which are part of a 300-strong herd that provides beef for the Queen and other members of the Royal Family.

The cattle, a traditional British breed protected by the Rare Breeds Survival Trust, were loaded into a lorry and driven away from a yard at Appleton Farm in West Newton on the Queen's Norfolk estate.

Tony Barratt, a tenant farmer who rents 300 acres from the Queen, owned the cattle and sells meat from the herd as 'Sandringham Beef' in local shops.

The meat, which is noted for its tenderness and fine grain, is regularly eaten by the Royal Family and guests at Sandringham.

Mr Barratt, 55, said he feared the chestnut-coloured cattle, which are naturally hornless, might have already been illegally slaughtered.

"I still have the passports for all the cattle so nobody would have been able to sell them legally," said Mr Barratt.