Prince Charles, the heir to the British throne, has tested positive for coronavirus, his household said.

Charles, eldest son of Queen Elizabeth, is 71 years old.

“The Prince of Wales has tested positive for Coronavirus,” Clarence House said in a statement. “He has been displaying mild symptoms but otherwise remains in good health and has been working from home throughout the last few days as usual.”

“The Duchess of Cornwall has also been tested but does not have the virus,” Clarence House said. The Prince and his wife, Camilla, are self-isolating at home in Scotland.

“It is not possible to ascertain from whom the Prince caught the virus owing to the high number of engagements he carried out in his public role during recent weeks,” the statement read.

A royal source said the Prince of Wales was tested on Monday and got the results on Tuesday. Charles has spoken to both Queen Elizabeth and his children.

He last saw the 93-year-old monarch on the morning of March 12 following an investiture, before the earliest time he would have been infectious.

“Her Majesty The Queen remains in good health,” Buckingham Palace said. “The Queen last saw The Prince of Wales briefly after the investiture on the morning of 12th March and is following all the appropriate advice with regard to her welfare.”

A royal source said that the earliest Charles would have been infectious was March 13.

Queen Elizabeth left London for Windsor Castle on March 19. She is with her 98-year-old husband, Philip.