Sources informed STV News, the BBC and The Times on Thursday of Murray's positive test. The three-time Grand Slam champion is in isolation at home and still hopes to travel to compete in Melbourne, Australia.
The 2021 Australian Open starts on Feb. 8. Murray planned on flying to Melbourne this week, but now will need to be granted permission for a later arrival. Other Australian Open competitors and officials are required to arrive in Melbourne over the next 36 hours.
Players at this year's Australian Open must pass a series of COVID-19 tests during a 14-day quarantine in Melbourne before they compete in the Grand Slam. They are allowed to practice during the quarantine.
Players will then play in warm-up events the week before the Grand Slam.
Murray, 33, also withdrew from the Delray Beach Open, the first tournament of the year. He said in a Dec. 31 news release that he wanted "to minimize the risks [of contracting COVID-19] ahead of the Australian Open" as an explanation for the withdraw from the Delray Beach, Fla., tournament.
Murray has a wild-card entry at the Australian Open, the first Grand Slam of the year.