Kearsley has the highest number of new coronavirus cases anywhere in the country, according to the latest figures.
Data from Public Health England for the week between September 6-12 shows there were 51 new infections registered in the borough, compared to 47 cases in the next highest area.
The numbers refer to Middle Super Output Areas (MSOA) - sections of Bolton with populations of around 7,000 people.
The area with the second highest number of cases over the same period is Alexandra Park, in Oldham.
Kearsley, which also includes the Stoneclough area, has consistently had the highest figures over the last few days, with the numbers rising from 45 cases in the week leading up to September 10.
But, Bolton Council says its public health team cannot put the rise down to any single outbreak.
A spokesperson for the council said: "We are aware of the case numbers for Kearsley and other MSOAs in the borough.
“Our investigations so far have not identified a particular driver of transmission.
"It is unlikely to be driven by a single factor and more likely a combination of community transmission and transmission within households"
Bolton's overall infection rate has fallen slightly today, down to 189 new cases for every 100,000 people in the town.
But this could change if testing figures are delayed as they were last week.
Wigan is also now in the coronavirus 'red zone' of more than 50 cases per 100,000, with only Stockport and Trafford still below that landmark.
