More than 9,000 Covid infections were linked to Euro 2020 football games monitored for the government’s mass events test scheme, and scientists have said the tournament generated “a significant risk to public health”.

An analysis of the third and final stage of the research programme, released on Friday, found that more than 85% of all the infections connected to the 49 days of various outdoor sport, music and entertainment events came from the eight Euros games involved, and mainly the semi-final and final.

Such were the disparities in Covid infections between Euros crowds and those who attended Wimbledon, another test event, that government scientists have raised the idea of football fans being allowed to take drinks to their seats, as happens at the tennis championships, to avoid dense crowds gathering around bars.

The study, jointly run by the culture department and Public Health England, found that 9.402 positive Covid tests emerged from fans at the Euro games, with 3,036 people reporting symptoms within two days of the game, indicating they were likely to have been infectious at the time of the match.

Ministers argue that across all three stages of the test programme, which also covered indoor venues, case numbers were largely similar to or below the general infection rates for the time, meaning mass events can take place safely.

But a study paper about the final phase, led by Dr Jenifer Smith, the deputy medical director for Public Health England, says that while the Euros were not typical, it is important to learn lessons from the scale of infection they brought.

“The Euro 2020 tournament and England’s progress to the Euro final generated a significant risk to public health across the UK even when England played overseas,” the report states. “This risk arose not just from individuals attending the event itself, but included activities undertaken during travel and associated social activities.”

Contrasting this with Wimbledon, where the show courts had up to 100% capacity but combined crowds of around 300,000 generated just 881 cases, the study notes: “Research teams present at each of these events have verbally reported stark differences in crowd and spectator behaviour.”

Aside from the issue of crowds around bars, the study says Euros spectators became gradually less compliant with rules on things such as masks, while the England v Italy final, which generated almost half of the Euros Covid cases, was marked by mass disorder, including the intrusion of ticketless fans.

“Euro 2020 was a unique occasion and it is unlikely we would see a similar impact on Covid-19 cases from future events,” Smith said. “However, the data does show how easily the virus can spread when there is close contact, and this should be a warning to us all as we try and return to a cautious normality once again.”

Oliver Dowden, the culture secretary, said: “We’ve shown that we can reintroduce mass sports and cultural events safely, but it is important that people remain cautious when mixing in very crowded settings.”

As well as the Euros and Wimbledon, the other events in the final phase were a series of international cricket matches, the Royal Ascot racing, the Open golf tournament in Kent, the Goodwood Festival of Speed, and the Download music festival.

Download had just 81 identified cases among the 10,000 people who attended over three days.

While the mitigation measures varied between events, entrants to all had to show that they were fully vaccinated, had Covid antibodies or had tested negative for the virus within the previous 48 hours. The one exception was at the Euro final, where the scale of disorder meant the checks were suspended.