Mercedes Formula 1 driver Lewis Hamilton will sit out this weekend's Sakhir Grand Prix in Bahrain following a positive COVID-19 test.
Mercedes says it will announce the replacement for Hamilton, who won last weekend's Bahrain GP, "in due course".
The team's official reserve drivers are Stoffel Vandoorne and Esteban Gutierrez, although Nico Hulkenberg - who has raced three times for Racing Point this year - is a possible candidate.
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A statement said: "The FIA, Formula 1 and Mercedes-AMG Petronas F1 Team can today confirm that during mandatory pre-race PCR testing for the Sakhir Grand Prix, Lewis Hamilton has tested positive for COVID-19.
"In accordance with COVID-19 protocols and public health authority guidelines in Bahrain he is now isolating.
"All contacts have been declared. The procedures set out by the FIA and Formula 1 will ensure no wider impact on this weekend's event."
The team said that it "regrets to announce that Lewis Hamilton has tested positive for COVID-19 and will be unable to take part in this weekend's Sakhir GP".
It added: "Lewis was tested three times last week and returned a negative result each time, the last of which was on Sunday afternoon at the Bahrain International Circuit as part of the standard race weekend testing programme.
"However, he woke up on Monday morning with mild symptoms and was informed at the same time that a contact prior to arrival in Bahrain had subsequently tested positive.
"Lewis therefore took a further test and returned a positive result. This has since been confirmed by a retest.
"Lewis is now isolating in accordance with COVID-19 protocols and public health authority guidelines in Bahrain.
"Apart from mild symptoms, he is otherwise fit and well, and the entire team sends him its very best wishes for a swift recovery.
"We will announce our replacement driver plans for this weekend in due course."
How Hamilton contracted the virus has not been revealed, but it is understood that the world champion has not deviated from the strict protocols that he has lived under all season.
After the Turkish Grand Prix, Hamilton returned to his home in Monaco as per normal, and ahead of the Bahrain GP he travelled to Dubai.
There, he spent some time with his family, who had all been tested before travelling and returned negative tests, as well as making a personal appearance at an event.
He left Dubai for Bahrain, where he had three further tests that all returned negative before it was confirmed on Tuesday he had contracted the virus.
Hamilton becomes the third F1 driver to miss a race due to COVID-19, after Racing Point drivers Sergio Perez and Lance Stroll were both forced to sit out races earlier in the season.