Monaco's Princess Charlene will not take part in public duties, including the principality's national day celebrations this week, while she recovers from ill health, the Monaco royal palace said on Tuesday.

The palace said Charlene would convalesce in a secret location and that she would only resume her public duties once her health allowed it.

"Their Serene Highnesses have both decided that a period of calm and rest is necessary to ensure the very best recovery for Princess Charlene’s health," the palace said.

"Having battled with poor health over the past few months, the Princess is currently convalescing and will continue to do so for the coming weeks," it added.

Charlene, a former Olympic swimmer who married Monaco's ruler Prince Albert in 2011 in a lavish ceremony, returned to Monaco earlier this month after spending much of the year in her homeland South Africa. 

Photographs at the time showed Charlene wearing a protective face mask surrounded by her husband and children in front of the palace's white stairways.

The palace said the princess needed time to recover from a "state of profound general fatigue."

Her stay in South Africa sparked speculation about a potential rift inside the royal couple - a claim the family denied.

The princess was admitted to hospital in South Africa in September for treatment for an ear, nose and throat infection which led her to collapse.

"As soon as her health permits, the Princess looks forward to once again carrying out her Princely duties and spending time with the Monegasques," the statement added.