The Duke of Cambridge should have made his coronavirus diagnosis public once he had recovered, a royal commentator has suggested.
Joe Little, managing editor of Majesty magazine, said William’s decision to keep his positive Covid-19 test a secret in April was “a retrograde step” in terms of transparency.
The news has only just emerged seven months later, with The Sun newspaper revealing that the duke did not want to alarm the nation.
It is understood that William followed guidance on isolation and other measures when a person tests positive, and that he appears to have made a full recovery.
Royal expert Mr Little said: “Was it wise on the part of Kensington Palace to suppress it?
“I suppose you could say that we’re living in extremely unusual times and it was done with the best of intentions.
“But, with the benefit of hindsight, I suppose it is questionable.”
Prime Minister Boris Johnson was being treated in intensive care in a London hospital in April after contracting coronavirus, while William’s father, the Prince of Wales, had been in quarantine after catching the disease in March.
William told one observer at an engagement: “There were important things going on and I didn’t want to worry anyone.”
Downing Street declined to comment on whether Mr Johnson was aware that the duke had tested positive in April.
The Prime Minister’s official spokesman said: “These questions are a matter for the royal household.”
The Sun reported that William, who carried on with telephone and online engagements, was treated by royal doctors as he isolated in Norfolk but that he was hit “pretty hard” by the virus and at one stage struggled to breathe.
Mr Little suggested: “I think, with the benefit of hindsight, it would have been sensible once he was fully recovered to say ‘Well, look, I’ve had it, but I’m OK now’.
“We could have found out at the end of April rather than in November.
“It’s inevitable that these things get out in the end.”
He added: “Is it the biggest of deals? I’m not sure it necessarily is but it kind of makes you wonder what else is being suppressed?
“It’s all about transparency these days and this is a retrograde step, I suppose.”
Royal author Penny Junor described the decision not to make William’s diagnosis public as “very odd”, saying it went against royal precedent.
Ms Junor said: “When I heard it, I thought ‘Surely it can’t be true because we would have been told any important news’.
“It’s very odd, because we do normally know things that are regarded as in the public interest if anything happens to one of our leaders.”
She cited being told whenever Charles was injured while playing polo and when William suffered a depressed fracture to the forehead after he was accidentally hit on the head with a golf club at school in 1991.
Ms Junor added: “I would have thought William having coronavirus was also in the spirit of that precedent.
“We perhaps should have known because he’s not a private individual.”
Charles’s coronavirus battle and making this publicly known allowed him to share his experience with others also facing the disease, the author added.
“Prince Charles was able to speak with and be alongside people who had also had it,” she said.
“Instead of being a sort of precious royal who was wrapped up in cotton wool and kept away and immune to the diseases that the rest of the world gets, he had suffered.
“And I think it might have been helpful if we’d known that William had also had the virus.”
In his first public engagement after recovering from mild symptoms, Charles revealed that he lost his sense of taste and smell.
He spoke of his personal experience with Covid-19 when he met frontline NHS staff and key workers in person with the Duchess of Cornwall in June.
Ms Junor added that it was perhaps a sign that William was setting out a new path for the royals in terms of what is deemed in the public interest.
“For the rest of us, one’s health is private. But William’s position is slightly different. But maybe that’s not the way it should be in the future – maybe he’s forging a new path here and maybe that’s no bad thing.”
Kensington Palace declined to comment.