Boris Johnson won’t need to quarantine, his office says, despite a positive test on his team.

Prime Minister Boris Johnson of Britain will not have to quarantine even though a member of the team that accompanied him to Scotland this week tested positive for the coronavirus during the trip, his office said on Friday.

A Downing Street spokeswoman said on Saturday that the prime minister had not been in close contact with the aide.

“The prime minister regularly visits communities across the U.K., and all aspects of visits are carried out in line with Covid guidance,” the spokeswoman said. “The prime minister has not come into close contact with anyone who has tested positive.”

The declaration that Mr. Johnson would not go into quarantine — even as British news reports said that the person who tested positive and several other officials have — threatened to revive a controversy over government officials’ adherence to Britain’s test-and-trace system. Each week under that system, hundreds of thousands of people who have come into contact with someone who has tested positive have had to isolate themselves.