Experts have urged the Government to reveal the source of contaminated eggs that led to a major outbreak of deadly salmonella which killed one Briton and left 200 ill.

Officials have revealed that the spate of illness is related to eggs imported from abroad, but have not yet specified where.

Meanwhile, health chiefs in Belgium today announced they are investigating a similar salmonella outbreak at a poultry farm that's said to have affected 300 people and contaminated eggs which are shipped to nine nations.

The UK is not yet listed as one of the affected countries although Poland, which supplies eggs to Britain, is. 

The Government was previously warned of the dangers of imported eggs in a major report published earlier this year by industry experts, which highlighted 'significant' safety risks of importing eggs from countries like Poland and Ukraine.

While most eggs on supermarket shelves are produced in the UK, increasing quantities are being brought in from overseas where farmers use practices that are banned in the UK. 

Egg imports to the UK have risen by 60 per cent since 2021, data shows. Exports from Ukraine jumped by 65 per cent in the last year alone.

Paul Wigley, a professor in animal microbial ecosystems at University of Bristol told the Daily Mail that the source of the contaminated eggs 'should be public information'.

'If necessary, restrictions should be imposed on importations.'

Professor Wigley added that non-British eggs come from a 'lower standard'.

'A UK-produced egg will come from a hen that's vaccinated against Salmonella,' he said. 

'Every flock is tested for Salmonella roughly three to four times, every two years. You're extremely unlikely to get Salmonella from a British egg – there's almost zero risk.'

Other experts have told the Mail that UK food safety officials 'will know where the contaminated eggs have come from' but 'are unlikely to reveal it'.

So far, 199 cases from the current outbreak have been confirmed in England, six in Scotland, one in Wales and one in Northern Ireland. 

The specific strain identified is Salmonella Enteritidis, commonly found in poultry and eggs.

More than a third of those affected needed hospital treatment, while two developed potentially life-threatening bloodstream infections, the UK Health Security Agency (UKHSA) said, and one died. 

The UKHSA yesterday confirmed that those affected had become sick after eating in cafes and restaurants.

It has identified five unnamed food businesses which two or more of those affected had reported attending in the week before getting symptoms.

Official guidance states that salmonella is typically caught by eating contaminated foods. As well as eggs, these include poultry, meat, raw fruit and vegetables and unpasteurised dairy products.

Cooking foods thoroughly usually destroys the pathogen, which is why runny yolks are higher risk.

The disease usually causes symptoms such as a fever and vomiting which then clear in a few days. But in rare cases it can be fatal, with infants, pregnant women, the elderly and those with weakened immune systems being most at risk. 

In March, the British Egg Industry Council (BEIC) warned the Government that the public may be exposed to 'significant' risks as a result of importing eggs from elsewhere in Europe. 

In its report, entitled Shell Shocked, the council found there had been an increase of 600 million imported eggs to the UK since 2021, largely driven by rising intake from Ukraine and Poland.

They raised particular fears over Ukraine's use of battery cages – small enclosures made completely of wire which have been banned in the UK since 2012 – on its chicken farms.

The BEIC said receiving imported eggs from Ukraine risked 'undermining the integrity of the British egg market' and raised 'significant food safety, economic, ethical and reputational concerns'.

They added: 'The principle is simple: if a production system is not legal in the UK, its products should not be allowed to enter the UK market, and neither should food produced to lower food safety standards.'

Furthermore, the report warned: 'Imports of eggs... may expose the British public to potential risks, including Salmonella, chemical residues, and eggs produced in conventional ‘battery’ cages'.

BEIC chief executive Nick Allen added: 'It is deeply concerning that imported eggs are once again under scrutiny in connection with a serious Salmonella outbreak.

'We have repeatedly raised concerns about the risks associated with imported eggs and egg products with Government, most recently through our Shell Shocked report.'

Meanwhile Kevin Coles, of the British Egg Information Service, today told the Mail that people have the right to know where their eggs come from, particularly in the case of an outbreak.

'We have been urging the Government to protect British consumers by banning imported eggs for a while,' he said. 

'But in the meantime, you can check if your eggs are British by looking for the British Lion mark.'

Jacquelyn McCormick, Head of Incidents at the FSA, said: 'We are working closely with the UK Health Security Agency and other partners to investigate an outbreak of Salmonella Enteritidis.

'The exact cause has not yet been identified, however investigations so far have identified links to eggs imported from outside the UK, mainly used by food service and catering establishments such as restaurants or cafes, as a potential source. 

'There is no evidence that UK-produced eggs are affected.

'While investigations continue, our advice around eating eggs remains the same. Eggs which are thoroughly cooked and handled hygienically should not present a food safety risk.

'Infants, young children, pregnant people and older adults should only eat runny or raw eggs if they have a British Lion mark or are produced under the Laid in Britain egg assurance scheme. This advice does not apply to those who are severely immunocompromised and require medically supervised diets.'

The outbreak comes at the same time Belgium battles its own Salmonella spread linked to eggs.

Around 300 people – who are as young as one and as old as 96 – are said to be ill, which is up from 236 in May.

The eggs are said to have also been distributed to France, Luxembourg, Czech Republic, Italy, Poland, Portugal, Spain and the Netherlands.

A major outbreak of Salmonella Enteritidis linked to eggs from Poland was seen between 2017 and 2020.

It saw almost 1,000 cases of Salmonella, most of which were found in the UK.