World champion Lewis Hamilton will miss this weekend's Formula 1 Sakhir Grand Prix in Bahrain after testing positive for coronavirus.
His team, Mercedes, said the Briton woke with mild symptoms on Monday and returned a positive result at a subsequent test and again at a retest.
Hamilton, who is now self-isolating, won the Bahrain Grand Prix at the same circuit on Sunday.
The 35-year-old said he is "devastated" to miss Sunday's race.
"I'm gutted not to be able to race this weekend but my priority is to follow the protocols and advice and protect others," he wrote in a post on Instagram.
"I am really lucky that I feel OK with only mild symptoms. Please look after yourselves out there. You can never be too careful."
Hamilton, 35, clinched his record-equalling seventh world title at the Turkish Grand Prix on 15 November.
Sunday's race will be the first Hamilton has missed since his F1 debut at the 2007 season-opening race in Australia.
He must return a negative test before returning to the paddock and therefore is a doubt for the final race of the season in Abu Dhabi on 13 December.
Mercedes said Hamilton was tested three times last week, including on Sunday at the Bahrain International Circuit, and returned a negative result on each occasion.
However, as well as waking with mild symptoms on Monday, he was also informed that a contact "prior to arrival in Bahrain" had tested positive.
Hamilton is the third F1 driver to test positive for coronavirus this season following Sergio Perez and Lance Stroll.
Who will fill in for Hamilton?
Mercedes have not said who will replace him but Belgian reserve driver Stoffel Vandoorne - the former McLaren F1 driver - will travel to Bahrain as planned after Tuesday's Formula E test in Valencia.
Vandoorne, who raced for McLaren in 2017 and 2018, is the obvious option for Mercedes but the team are also expected to explore the possibility of using Williams driver George Russell.
The 22-year-old Briton is a Mercedes protege and is being prepared for a potential switch to the factory team in F1 at some point in the future.
As a result, Mercedes F1 boss Toto Wolff could be tempted by the idea of giving Russell a one-off drive - which could stretch to two races if Hamilton is not free of Covid before the season-ending Abu Dhabi Grand Prix the following weekend.
However, Russell is under contract to Williams until the end of next season and the British team would have to agree to release him temporarily before Mercedes could put him in Hamilton's car.
When Mercedes were exploring their contractual options for 2021 earlier this year, they asked Williams whether they would be prepared to release Russell for next season, to see where they stood prior to confirming Valtteri Bottas. Williams said at the time that they were not prepared to release him from his contract a year early.
Williams are last in the constructors' championship but only three points behind Haas and, as Russell is their lead driver who has comprehensively out-performed team-mate Nicholas Latifi this season, they may not be keen on releasing him.
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