Stroll, 21, withdrew from the October 11 race at the Nurburgring in Germany after falling unwell.
He returned a negative test on the Tuesday before the grand prix, but, despite displaying flu-like symptoms over the ensuing days, he was not re-tested for Covid-19.
Stroll left Germany to take a private jet to his home in Switzerland on the morning of the race. He was tested that evening, and was informed the following day he had contracted the virus.
— Lance Stroll (@lance_stroll) October 21, 2020
Stroll, who isolated at home for 10 days, says he is now clear of coronavirus and is fit to take part in this weekend’s Portuguese Grand Prix.
The PA news agency has also been told that his father Lawrence, who was not in Germany for the Eifel Grand Prix or at the previous round in Russia, returned a positive sample on the same day as his son.
Racing Point say the 61-year-old displayed no symptoms of the illness and spent 10 days in quarantine at his Swiss home.
— BWT Racing Point F1 Team (@RacingPointF1) October 21, 2020
Racing Point are facing questions over their handling of the incident after failing to report the extent of Stroll’s case to the FIA, and as to why he was allowed to travel home despite showing signs of the virus.
Racing Point say they followed FIA protocols which ensures all F1 personnel must be tested every five days and were advised by a doctor that Stroll’s symptoms were not indicative of Covid-19.
Stroll becomes only the second driver from Formula One to contract the illness after his Racing Point team-mate Sergio Perez also returned a positive test on the eve of the British Grand Prix in August.
The Mexican missed the Silverstone race and the subsequent 70th Anniversary Grand Prix at the same venue.
“Racing Point can confirm that Lance tested positive for Covid-19 on Sunday 11th of October,” said team principal Otmar Szafnauer in a statement on Wednesday.
“Lance had left the team bubble in Germany on Saturday 10th October as he was unable to compete due to the effect of a recurring stomach upset.
“Lance had first reported an upset stomach during the Russian Grand Prix week and subsequently tested negative for Covid-19 several times, tests taken in line with both the FIA and Racing Point’s own protocols.
“He also tested negative before arrival in Germany in the official pre-event test for the Eifel Grand Prix. The upset stomach symptoms returned on Saturday which forced Lance to withdraw from the race and stay in his motorhome away from the paddock.
“He consulted with a doctor who did not believe his symptoms indicated Covid-19 and did not advise a test was necessary. Based on this clinical assessment, at the time there was no requirement to inform the FIA as to the nature of the illness.
“All members of the Racing Point team at the Eifel Grand Prix returned to the UK via a private charter flight and all tested negative upon their arrival, and again in their pre-event test for the Portuguese Grand Prix.”