Data gathered at the recent World Snooker Championships suggests theatres pose almost no risk in spreading COVID, with just four infectious cases detected among 11,000 visitors to The Crucible venue last month.

The Telegraph, citing Whitehall sources, said unreleased Events Research Programme documents show a minute risk of infection from indoor gatherings in what could be a boost for the case for reopening as planned on June 21.

The snooker tournament took place over 17 days from April to May, with crowds initially at 33-per-cent capacity and rising to 100-per-cent for the two-day final. It is unclear how many of those positive tests were returned when the Crucible was allowed to operate at full capacity and without social distancing.

A Whitehall source, cited by The Telegraph, said: “The numbers are very low. The Government is sitting on very good evidence about where the risks lie when removing social distancing – and the evidence from the pilot study in Sheffield shows the risks for theatres are very low.”

The Telegraph report comes after theatre impresario Lord Lloyd Webber earlier this week said he would open his West End venues on June 21 regardless of whether the Government chooses to delay its long-held reopening target date.

He said: “I’ve seen the science from the tests, don’t ask me how. They all prove that theatres are completely safe, the virus is not carried there. If the Government ignore their own science, we have the mother of all legal cases against them. If Cinderella couldn’t open, we’d go, ‘Look, either we go to law about it or you’ll have to compensate us’.”

LW Theatres owner Lloyd Webber and the Night Time Industries Association have each suggested they will instigate legal challenges should the Government seek to delay the end of social distancing on June 21.

The Government is expected to announce on Monday (June 14) whether it will maintain the planned date of June 21 for Step 4 of its roadmap out of COVID restrictions, first announced in February. Some scientists have suggested that there should be a delay due to the risk of rising cases believed to be linked to the Delta COVID variant so that more people can be vaccinated in the coming weeks.