Newquay has become England's Covid capital as a major music festival was hosted with 50,000 attendees as infections spiked in the area.
The Cornish town recorded up to 1,110 cases per 100,000 people in the week ending August 14 - nearly quadruple the average rate in the country.
Boardmasters Festival went from August 11 to 15 - meaning the full impact of the five-day event on transmission rate will not be seen until later this week.
Attendees were required to show proof of double vaccination, natural immunity or a recent negative lateral flow test to enter the festival.
The festival has said it has done all it could to limit the spread of Covid.
Unvaccinated festival-goers who were eligible to attend were urged to attend a walk-in vaccine clinic, which was set up in the festival car park.
Public health officials say they are "monitoring the data" after a number of people claimed to have tested positive for the virus after attending the festival.
Coventry councillor Nathan Griffiths was one attendee who claimed to have contracted Covid at the event.
Newquay, and more widely Cornwall, was already seeing a sharp increase in cases as it is thought the increase of staycations could be the culprit.
Government data shows Newquay East had the highest infection rate of any authority in England by August 14 - recording 1,174 cases per 100,000 people.
It was slightly above Yarborough in Lincolnshire (1,124).
Newquay West had the eighth highest rate in the country at 864.5 per 100,000.
Councillor Griffiths claimed he contracted the virus at the festival.
He tweeted: "Like many, I caught Covid at Boardmasters despite the mandated day 1 + 3 lat-flows [rapid lateral flow tests].
"No complaints as I knew the risks, however, means either lat-flows aren't reliable for such events, or Covid-positive people faked negative results. A lot to learn here for gov/event organisers."
Another attendee said: "Went to Boardmasters and got Covid, everyone I know has it too. Not fun, hope everyone else with it recovers soon."
A third tweeted: "100 per cent of the people we know who attended Boardmasters have come home and tested positive for Covid. Not even from the same groups of friends."
A spokesman for Boardmasters said it had done all it could to limit the risk of Covid.
He said: "In addition to having the advantage of perhaps the best ventilated venue in the country, we asked festival goers to play their part in reducing the impact of potential infection by showing proof of full vaccination, a negative lateral flow test or immunity from having had the virus before they could join us on site.
"All staff, regardless of vaccination status, had to show a negative test every 48 hours and all campers were asked to re-test before they could come back into the arena on Friday.
"By giving those who had to isolate on festival dates, or who tested positive for Covid-19 before or during the festival, the ability to roll-over their tickets to 2022, we made sure they would not lose out by following the guidance and helping to reduce infections.
"We are processing over 450 requests from those affected and we are very grateful to them for doing their bit for the entire Boardmasters community.
"Like any town, we cannot eliminate risk entirely and, while it is still too early to see from the data if there has been any impact on Covid-19 cases, there are likely to be anecdotal reports of some people who were at the festival among those who test positive in the days following."
It comes as Covid cases have increased in almost 60 per cent of areas in England in the last week.
The latest data for infection rates reveal that 184 out of the 312 local areas have reported a rise in fresh infections.
Experts are attributing the rise in cases to the staycation boom.
Liberal Democrat MP Andrew George, who was elected to Cornwall Council in May, told MailOnline : "Resort areas of Cornwall appear to have the highest and still growing levels of Covid.
"I don't think it is primarily caused by holidaymakers themselves, but by poor infection control rules."