Chief Medical Officer Professor Dame Sally Davies has previously said that 'bute' poses only a very low risk to humans. She said:
Horse meat containing phenylbutazone presents a very low risk to human health.
'Phenylbutazone, known as bute, is a commonly used medicine in horses. It is also prescribed to some patients who are suffering from a severe form of arthritis.
The levels of bute that have previously been found in horse carcasses mean that a person would have to eat 500 - 600 one hundred per cent horsemeat burgers a day to get close to consuming a human's daily dose.
And it passes through the system fairly quickly, so it is unlikely to build up in our bodies.
More top news
Brexit, the Duke of Edinburgh, cervical cancer and the Spice Girls are on the fronts.
PM to set out her next steps after last week’s overwhelming Commons defeat for her deal for leaving the EU.
The Labour leader says he will not meet Theresa May for Brexit talks unless she takes no deal off the table.