Prince William has responded to mounting public “uncertainty” over his wife Kate’s health and disappearance from public life.

The Princess of Wales’ private recovery from abdominal surgery has gripped the internet and triggered conspiracies, questions and memes on her whereabouts.

Without any solid information from Kensington Palace, the void has been filled by increasingly speculative headlines around the world, as well as irreverent commentary online.

People magazine on Wednesday released its latest cover story in which royal biographer Sally Bedell Smith said the lack of transparency surrounding the royal family was creating “uncertainty”.

The article was headlined “Royal Family in Turmoil as Demands Mount for More Transparency: ‘There Is Too Much Uncertainty’ “.

“Everybody feels unsettled by uncertainty, and there is too much uncertainty that is surrounding the monarchy right now,” Bedell Smith said.

“Queen Elizabeth used to say, ‘I need to be seen to be believed.’ It is important for Charles and his reign for the public to know a little bit more.”

However, a spokesperson for the Prince of Wales told People the senior royal was not getting drawn into the online chatter.

“His focus is on his work and not on social media,” the statement said.

Kate, who had major surgery in January, was spotted in public this week for the first time since her hospitalisation, being driven close to her home in Windsor following huge speculation about the state of her health.

An image circulating online showed the princess, wearing sunglasses, sitting in the front seat of a car being driven by her mother, Carole Middleton.

But the speculation online has taken on a life of its own, with some even questioning whether the figure in the car was actually the Princess of Wales.

Kate left hospital on January 29 and is recuperating at her Adelaide Cottage home close to Windsor Castle. She is not expected to return to official duties until after Easter.

In late February, a spokesperson for the Waleses: “We were very clear from the outset that the Princess of Wales was out until after Easter and Kensington Palace would only be providing updates when something was significant.”

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Earlier this week, the British Ministry of Defence appeared to have inadvertently revealed on its website that Kate was expected to review troops ahead of the Trooping the Colour in June.

It appeared to be confirmation of what was likely to be Kate’s first major engagement since undergoing the operation. However, the reference has since been deleted from the website.

Prince William returned to royal duties in early February following his wife’s surgery and his father the King’s cancer diagnosis and start of treatment.

Then William’s abrupt no-show at a memorial for his godfather, King Constantine of Greece, on February 27 triggered a barrage of conspiracies.

Kensington Palace said William cancelled at the last minute because of an unspecified “personal matter”. That further fuelled speculation and concern among royal watchers, as the long-planned event was held within walking distance of his home.

-with AAP