Knowsley is among 20 council areas in England which could be at risk of a local lockdown, it has been reported.
The borough has been designated as facing one of the worst coronavirus outbreaks in England by Public Health England, according to a classified document seen by the Observer and the Guardian.
Knowsley is placed at 19 of the top 20 council areas for the worst coronavirus outbreaks in England.
The list was calculated by taking into account the number of cases per 100,000 people, and what proportion of people test positive for the virus, the newspaper said.
Between 28 June and 4 July 2% of people who underwent coronavirus tests in the borough tested positive for the virus.
Public Health Officials have ordered the army to deploy extra mobile testing unites that will be sent into a series of hotspots across the country from this weekend.
The news comes as evidence begins to emerge that the easing the coronavirus lockdown is leading to a spike in new cases of Covid-19.
Earlier this week local health chiefs took action after an outbreak of coronavirus among young people in parts of south Liverpool but council health bosses also warned that there had been a number of cases in Knowsley.
Speaking to the ECHO on Friday, Knowsley's Director of Public Health, Dr Sarah McNulty, said: "I can't stress enough how important it is to stay at home and get tested if you develop symptoms, particularly with lockdown measures easing and pubs and bars now reopening.
"It is so important that social distancing is part of your everyday life – you don't know who has it and who could be spreading it, but if you're within two metres of them for more than 15 minutes and they test positive, you will have to self-isolate for 14 days."
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Leicester remains at the top of the list with 5.7% of those tested having the virus followed by Kirklees (5%), Bradford (4.3%), Blackburn with Darwen (4.9%).
On Thursday, the top ten local authority with the worst real time coronavirus outbreaks was passed to local health bosses.
According to the document, the 20 areas listed are "currently under investigation by the local public health protection teams".
The Department of Health and Social Care told the Observer it did not have a set trigger for a local lockdown.
It said the list of 10 local authorities with the highest weekly incidence of coronavirus is publicly available as part of its surveillance reports.