NINE supermarkets have revealed the amount of contaminated chicken sold in their stores.

The data, published in a report by the Food Standards Agency (FSA), shows the level of campylobacter found in samples taken at all major supermarkets in the UK.

Reports on the poultry bacteria have been released by the FSA since around 2014, with the issue becoming the subject of national attention in 2017 when the extent of contamination in stores was exposed.

That year, supermarkets across the country recalled chicken products as a result of health concerns due to the contamination levels.

Released every quarter, data from early 2019 revealed that supermarkets were within FSA guidelines - though had experienced an increase since late 2018 records, Wales Online reports.

Illness usually resolves on its own with experts recommending fluids, rest and painkillers - with serious cases often requiring antiobiotics.

However, if infection does not cease with such treatment, the results can be dangerous as complications can lead to severe medical conditions.

These include the development of septicemia and meningitis, as well as the potentially paralysing condition Guillain Barre Syndrome.

The latest figures for April to June 2019 show on average across the nine major supermarkets, 3.6 per cent of chicken samples tested positive for the highest level of contamination.

To be considered such, samples contain more than 1,000 colony forming units per gram (cfu/g) - enough to lead to food poisoning.

This collective average is significantly lower than the FSA's target of less than 7 per cent in the high category, though is slightly higher than the 3.5 per cent average between January and March this year.

The supermarkets have however made progress in reducing the second most serious category - cfu/g 100 to 1,000 - which had levels of 15.1 per cent earlier this year before reducing to 12.1 per cent for the most recent quarter.

Individually, Aldi, Asda, Marks & Spencer, Morrisons and Tesco reduced their high level contamination between April and June 2019.

These five supermarkets were the only ones to have seen an increase in levels during the first three months of the year.

The Co-op , Lidl, Sainsbury's and Waitrose each saw an increase in the latest data released.

All nine major UK supermarkets successfully kept high level contamination below the FSA target of 7 per cent maximum.

The best performing for the latest quarter was the Co-op, which had the lowest figure (1.8 per cent) despite individually having seen an increase from the previous 0.9 per cent figure (Jan to Mar).