So far, 166 cases of coronavirus have been confirmed at Rowan Foods in Wrexham, North Wales.
Public Health Wales said in a statement: “We are working with Betsi Cadwaladr University Health Board to urgently contact just over 300 workers that have not yet presented for testing.
“As we would expect with any focused track and trace process, we will identify additional asymptomatic cases.
“Finding these cases does not mean that the rate of infection in the Wrexham area is increasing as a whole.
“There is no evidence that Rowan Foods is the source of the outbreak.
“The multi-agency team managing the outbreak with Public Health Wales will continue to review the situation and work with the employer, their workforce and wider community to bring this outbreak to a swift conclusion.”
In April workers from the firm, which supplies the UK’s top supermarkets, walked out in an apparent protest over what they claimed was a lack of protection from coronavirus.
Rowan Foods is the latest food processing plant to to experience a COVID-19 outbreak.
Recently, the Princes tinned food factory in Cambridgeshire closed down to enable deep cleaning to take place after 14 staff members tested positive for the virus.
In North Wales, the 2 Sisters factory in Llangefni, Anglesey also tested around 158 of its employees for coronavirus.
This is a breaking story. More to follow…