LONDON — Prince William caught the novel coronavirus in the spring around the same time that his father, Prince Charles, also tested positive, according to various British media reports.

The Duke of Cambridge, 38, was left “struggling to breathe,” according to the Sun newspaper, which first published the story.

The British tabloid said that William, the second in line to the throne, kept the diagnosis secret because “he didn’t want to alarm the nation.” His diagnosis came a few days after the palace revealed in late March that Charles, the eldest son of Queen Elizabeth II, had the virus.

A spokeswoman for Kensington Palace said Sunday evening that the palace did not want to comment on the reports.

Charles, 71, had mild symptoms and lost his sense of taste and smell. He later said he “got away with it quite lightly.” He and his wife, Camilla, who tested negative, self-isolated separately at Birkhall, his royal residence in Aberdeenshire, Scotland.

British Prime Minister Boris Johnson was also stricken with the virus in late March and spent several days in a hospital in early April, including three nights in intensive care, where he received supplemental oxygen. On the same night that Johnson was hospitalized, the queen delivered a rare and rousing televised speech to the nation — only the fifth such address during her long reign — to reassure Britons that “better days will return.”

William was treated by palace doctors and isolated at Anmer Hall, his family’s home in Norfolk, the Sun said.

Despite his illness, William reportedly carried out 14 royal “engagements” in April. In one, he opened Nightingale Hospital in Birmingham via videolink. In another video,William and his wife, Catherine, Duchess of Cambridge, spoke to teachers and students at an elementary school that stayed open during the first shutdown of the pandemic to thank them for their support.

The royal couple appeared upbeat in the video. At one point, Kate jokingly chided her husband for eating all the chocolates in the house.

The news comes as England prepares to head into a second national shutdown, which begins Thursday and is set to last for at least four weeks.

On Monday, the queen, 94, and the Duke of Edinburgh, 99, traveled from their Sandringham estate in Norfolk to Windsor Castle, where they stayed during Britain’s first lockdown earlier in the year.