Harvesting has been allowed to restart at an oyster farm shut down by officials as an investigation continues into reports of people falling ill after eating the shellfish.

It was revealed yesterday that Canterbury City Council, the Food Standards Agency and Public Health England are examining the cases involving produce caught by the Whitstable Oyster Company.

KentOnline understands that at least 100 people had suffered bouts of sickness and diarrhoea potentially linked to a batch which was withdrawn by authorities on June 27.

But now city council spokesman Leo Whitlock says the farming has resumed at the site in Whitstable, as investigators continue to try to work out "what went wrong".

"A new notice has been issued which does not prevent the harvesting or processing of oysters but stops the supply and sale," he explained.

"The supplier in question has been asked to review what went wrong and ensure its procedures and systems will prevent a problem from happening again.

"Allowing oysters to be harvested and processed allows everyone to ensure systems are operating correctly."

Harvesting was voluntarily stopped at the site on June 28, before the city council served a notice enforcing this two days later.

KentOnline understands investigations are being carried out into whether Southern Water sewage releases in the area impacted the condition of the oysters.

The water firm's website shows there were 13 discharges from pipes in Tankerton, Swalecliffe and Gorrell between June 16 and June 18.

Despite admitting the releases are a concern, a spokesman for Whitstable Oyster Company insists the results of its tests have not given it "any cause for concern".

“We are working with the city council to get our oysters back in the market," he said.

"Harvesting and purification has resumed. As of yet none of our oysters have tested positive for norovirus and are within acceptable limits for Ecoli as set by the government.

"There have been no traces of norovirus in any of our oysters over the past year.

"Southern Water’s activities and continued use of combined sewer overflows do affect water quality and are an ongoing concern.

"However, our oysters are tested regularly for e-coli and norovirus and all oysters harvested undergo a 42-hour purification process at our facilities at the East Quay.

"There have been no traces of norovirus in any of our oysters over the past year..."

"None of the results of those tests, conducted very recently and on the batch allegedly involved, have given any cause for concern.”

The company spokesman previously stressed that the recent Southern Water sewage leaks in Thanet "will not affect the water quality in Whitstable as it is too far away".

This comes as the Centre for Food Safety (CFS) in Hong Kong suspended imports of raw oysters farmed by the Kent firm, after a number of cases of food poisoning.

A CFS spokesman noted that pathogens - such as norovirus, chemical contaminants or natural toxins - can accumulate in the shellfish "if they are grown in or harvested from contaminated water".

He added: "We were notified of several food poisoning cases which involved consumption of raw oysters at one restaurant in Sha Tin and one restaurant in Causeway Bay.

"The CFS conducted investigations at the restaurants concerned and found that both restaurants had sold raw oysters from the Whitstable Oyster Company in the United Kingdom supplied by the same local supplier.

"As well, we received a notification from the UK's Food Standards Agency that raw oysters supplied by Whitstable Oyster Company were suspected to be contaminated with norovirus.

"For the sake of prudence, we have immediately instructed a suspension on the imports into and sale within Hong Kong of all raw oysters produced by the company."

Anyone who has vomiting or diarrhoea symptoms and is concerned about their health should phone NHS 111 or their GP for advice.

Read more: All the latest news from Whitstable