Public health experts have called for an investigation into whether the decision to allow the Cheltenham racing festival to go ahead in early March led to a rise in coronavirus cases locally.

Mortality figures compiled by the Health Service Journal show that Gloucestershire hospitals NHS trust, which covers Cheltenham, has recorded 125 deaths, roughly double that in two nearby trusts at Bristol (58 each), and those covering Swindon (67) and Bath (46).

The trust declined to comment on the data, while senior officials at Gloucestershire council said there were “many factors” that could have influenced the death totals and comparisons between trusts in the west of England were “not possible”.

But Prof John Ashton, a former director of public health for Cumbria, said the figures “deserve to be properly investigated. We know the Festival went ahead and a lot of people will have attended and worked there. It’s important we learn about what the potential is for coronavirus transmission at public events”.

At Monday’s daily coronavirus press conference, Angela McLean, the government’s deputy chief scientific adviser, said there should be an investigation into the epidemiological consequences of another March sporting event, the Champions League tie at Anfield between Liverpool and Atlético Madrid.

“I think it would be very interesting to see in the future when all the science is done what relationship there is between the viruses that have circulated in Liverpool and the viruses that have circulated in Spain,” she said.

The Cheltenham Festival is one of the highlights of the racing calendar. This year’s event, from 10-13 March, was attended, organisers say, by 125,000 people often in packed stands, just as awareness of the seriousness of the coronavirus crisis was emerging.

On 16 March, fresh modelling from Imperial College prompted an emergency rethink on how to deal with coronavirus and the lockdown began on 23 March. But questions have been raised about whether the UK should have acted sooner.

Ministers encouraged Cheltenham’s organisers to go ahead – a decision that was again defended by the culture secretary, Oliver Dowden, as recently as Monday morning. “The risk at mass gatherings was no greater or less than it would have been in pubs or restaurants, and the advice at that point was that we did not need to ban mass gatherings,” he said.

Opposition councillors in Gloucestershire county council, which is run by the Conservatives, said they want to ask public health officials further questions this week. Paul Hodgkinson, the council’s Lib Dem group leader, said: “I think it is concerning. Gloucester and Cheltenham has been described as a hotspot in the south-west.

“I’ve asked the question why. I don’t think there is a definitive answer. There perhaps never can be. People are asking out loud whether the number of deaths is connected to the festival. We know anecdotally that some people who attended became ill.”

All queries to Gloucestershire NHS trust were forwarded to Gloucestershire council, which is responsible for public health. Sarah Scott, Gloucestershire’s director of public health, responded to questions about the impact of the festival on local death rates with caution.

“There are many factors that could influence the number of cases in an area, including population density, age and health profile and the position of an area on the pandemic curve. It is also not possible to make comparisons between hospital trusts across the region as they all serve populations of differing size and characteristics,” she said.

There have been anecdotal reports of people who attended Cheltenham falling ill with coronavirus symptoms, including Andrew Parker Bowles, the former husband of the Duchess of Cornwall, the comedian Lee Mack and the footballer Charlie Austin.

One attendee, David Hodgkiss, 71, the Lancashire county cricket club chairman, died of the disease in early April. But there is no firm evidence to suggest he or any of the others caught coronavirus at the race meeting.

Dr Andrew Preston, a reader in microbial pathogenesis from the Milner centre for evolution at the University of Bath, said the lack of community testing and tracing meant it may never be possible to know whether Cheltenham contributed to the spread of Covid-19.

But he said the mortality figures for Gloucestershire hospitals NHS trust raised questions. “If you look at the numbers by dates there is a general pickup over time, that is what has been seen nationally, but that appears to be greater for Gloucester than elsewhere in the region.

“This does coincide with around two weeks after Cheltenham, which puts this in the right time frame for these infections at around the time of the festival.”

The Jockey Club, which organises the premier event in the National Hunt calendar, declined to comment. Most racing professionals living in the Cheltenham area have consistently defended the decision to go ahead with the festival.