Around 200 workers have gone into quarantine at a farm in Herefordshire after 73 members of the site's workforce tested positive for coronavirus.
The outbreak took place among employees at vegetable producer AS Green and Co, which is located in the village of Mathon near Malvern.
A joint statement from Public Health England (PHE) Midlands and Herefordshire Council said that the workers were being told to remain on site for the duration of their time in quarantine.
Officials are treating the group as "one extended bubble", since all the members of the workforce live in mobile homes on the farm during the harvesting season.
The council added that it was arranging deliveries of food and other supplies to the residents during their self-isolation.
Katie Spence, PHE Midlands health protection director, said the farm had implemented infection control measures because of the pandemic.
Ms Spence said in a statement: "Despite these measures, a small number of workers became symptomatic earlier this week and they and a few close contacts among the workforce were tested initially and found to be positive."
She added that the whole workforce was then tested as a precaution and that almost all of the results have now come back.
In response to the outbreak, a spokesperson for AS Green and Co, which specialises in growing beans, said it was prioritising its "hardworking" staff.
A statement on the farm's website confirmed that it was closed to visitors and that the workers would remain on site.
"Our workforce and local community are our priority at this difficult time and we continue to follow the guidance of the relevant bodies to ensure that the spread of the virus is controlled and our workforce is supported," the statement said.
"Public Health England advises that it is very unlikely Covid-19 can be transmitted through food or food packaging, so shoppers can remain confident buying British fruit and veg," it added.
Karen Wright, Herefordshire's director of public health, urged anyone with coronavirus symptoms to be tested.
Ms Wright said: "While Herefordshire is the first to experience an outbreak of this kind, this is not unexpected. Our priority is to protect the health and wellbeing of all residents in our community.
"Prompt testing on the farm has allowed us to understand transmission and control the spread of infection.
"We continue to support the farm management, their workers, who form an important part of our local economy, and the local community through this challenging time," she added.
Following the Pick for Britain campaign - an initiative to bring UK workers and farmers together to prevent crops rotting in the ground during the pandemic - the farm said it had received more than 300 applications.
On the firm's website, it says workers are expected to share accommodation at Rook Row Farm, while there is a recreational building with a pool table, dart board and TV for all employees.
Mandatory face coverings in shops here not ruled out, Page 7