Hygiene inspectors have warned that more diseased meat could end up in sausages and pies because of changes to safety checks in slaughterhouses.
Ron Spellman, a British meat inspector with 30 years' experience, told the BBC that new regulations which took effect from June 1 risked diseased parts of animals going undetected.
Mr Spellman, who is director-general of the European Working Community for Food Inspectors and Consumer Protection (EWFC), which represents meat inspectors across the EU, said: "Last year we know that there were at least 37,000 pigs' heads with abscesses or tuberculosis lesions in lymph nodes in the head. They won't be cut now.
"There's no way to see those little abscesses, little tuberculosis lesions without cutting those lymph nodes."
Around eight million pigs a year are slaughtered for meat in the UK.
Meat from pigs' heads is recovered by specialised parts of boning plants and goes into pies, sausages and other processed foods.
Inspectors used to cut open pig carcasses to check for signs of disease.
Under new European regulations, supported by Britain's Food Standards Agency (FSA), they will have to rely on visual checks alone.
The new regulations have been drawn up by the European Food Safety Authority but are based on scientific advice from the FSA.
The FSA's chief operating officer, Andrew Rhodes, told the BBC it was better to have a hands-off system using visual checks to reduce cross-contamination, because bugs like E. coli and campylobacter are causing scientists more concern.
He said: "The risks to the consumers are increasingly from microbiological and pathogenic hazards and that's what we must control.
"We cannot simply ignore the risks that are brought by touching, cutting and handling products that are later going to go on to be cooked and eaten, we have to do this properly."
A Department for Environment, Food and Rural Affairs (Defra) spokesman said: " The changes to the meat inspections will mean less cutting and handling of carcasses and offal, reducing the potential risk of harmful bacteria spreading onto the meat.
"Pigs will continue to be inspected for lesions by a vet and again after slaughter by a meat inspector. All pigs for export will be inspected using the methods agreed with the markets we export to."
Shadow food and farming minister Huw Irranca-Davies said he had called for an urgent meeting with the FSA, which he hoped would take place in the next few days, "to ask why this change has come about".
Mr Irranca-Davies said: "We want categorical assurances that this does not in any way jeopardise consumer safety or Britain's reputation as a supplier that operates to the highest possible standards."