Two Tory MPs accepted £2,400 worth of tickets to the Cheltenham Festival just days before the UK went into coronavirus lockdown.
It's feared the gathering of more than 250,000 people helped spread the virus widely across the country.
Shipley MP Philip Davies and former minister Caroline Nokes accepted eight tickets between them to the horse racing event from GVC Holdings, the sports betting giant which owns Ladbrokes and Coral.
Mr Davies accepted six tickets, worth £300 each, but refused to say whether he had used them.
He said: "I have absolutely nothing to say to the Daily Mirror."
Ms Nokes accepted two tickets, also worth £300 each.
She was photographed at the event, wearing a grey suit with pink checks and a shocking pink hat and matching scarf.
Both MPs registered the gifts with Commons authorities - stating they would have access to a VIP hospitality box during their visit.
Ms Nokes said: “I accepted the tickets and declared them in accordance with the rules, which clearly you can establish from the register of members’ interests.
“As you know it was prior to the lockdown being declared and there were no restrictions on movement.”
Ms Nokes added a number of other MPs also attended the races on the same day, including Shadow Security Minister Conor McGinn.
Mr McGinn confirmed he attended the event in his capacity as chair of the All Party Parliamentary Group on Racing.
He said: "I get an annual metal badge from the Racecourse Association which allows me admittance to race meetings across Britain over the course of the year, including Cheltenham, which is owned by the Jockey Club."
Mr McGinn registers the badge as a benefit with Commons authorities at the start of each year.
He added: "I’m heavily involved in horse racing, not least because Haydock Park Is in my constituency. It is currently being used as a COVID-19 testing site for NHS staff in the North West."
Professor Sir David King said yesterday (WED) that the government had waited too late to ban large gatherings like Cheltenham, and that delay had cost lives.
He told LBC Radio: “Imagine, 16th March (sic), having a horse race go on with a massive crowd at Cheltenham.
“We didn’t manage this until too late and every day’s delay has resulted in further deaths in the United Kingdom.”
The Cheltenham Festival ran from Tuesday, March 10 to Friday, March 13.
At the time, Boris Johnson was still holding out on banning large gatherings, despite Scotland issuing such an order on March 12.
The Government eventually banned gatherings of more than 500 people the following weekend.
The Organisers of the horse racing festival defended their decision to go ahead when concerns were raised that attendees had reported symptoms after the event.
Comedian Lee Mack tested positive for Covid-19 after spending two days at the festival - with a friend reportedly saying he believed he caught it from a driver on his way to the event.
And the Times reported Andrew Parker Bowles, the former husband of the Duchess of Cornwall said he believes he “probably got it on the Wednesday or Friday I attended Cheltenham”.
A spokesperson said: “The Festival concluded three weeks ago and went ahead under the clear and ongoing guidance from the government and its science experts throughout, like other popular sports events at Twickenham [and] Murrayfield, 10 Premier League matches and the Uefa Champions League [between Liverpool and Atlético Madrid] at Anfield that same week.
“We promoted the latest public health advice and introduced a range of additional hygiene measures at the event, including hundreds of hand sanitiser dispensers and extra wash basins.”