Though remaining coy on specifics, Albert added: “Her return went pretty well in the first few hours and then it became pretty evident she was unwell.
“She was overwhelmed and couldn’t face official duties, life in general or even family life.”
The prince added, in his interview with People magazine: “She has lost a lot of weight, which made her vulnerable to other potential ailments. A cold or the flu or, God help us, Covid.”
Charlene married into royal life, having previously represented South Africa in the 100-metre medley relay at the Sydney Olympics in 2000.
She met Albert the same year at the Mare Nostrum swimming competition in Monte Carlo, Monaco and ultimately married the prince in July 2011.
In a November 2010 Tatler interview, months before Charlene became Princess of Monaco, she opened up about her royal encounters and the trials of living in the principality.
She was also full of praise for Harry, who she had met at a polo match that year.
Charlene said: “I met Harry at a polo match in July.
“I’m really hoping I get to know him better.”
Charlene also spoke out about the loneliness she had encountered since moving to glittering Monaco from South Africa.
The former backstroke swimmer said: “The people I mixed with in Monaco didn’t relate to my South African mentality or humour.
“Of course, I’ve been subject to jealousy, but that comes with the territory.
“Although I have met some wonderful people since I’ve been living in Monaco, I regard them all as acquaintances.
“I only have two people I consider friends here.”
Charlene had been living in Monaco for four years at the time of the interview, while she had also failed to fully settle into royal life almost a decade later.
In 2019 Charlene spoke about how she often felt homesick and couldn’t help but appear sad in photographs.
The Princess of Monaco was speaking during a difficult year which saw her father undergo surgery in South Africa and two of her friends pass away in just 10 days.
Speaking to South African magazine Huisgenoot, Charlene said: “People are very quick to say, ‘Oh, why isn’t she smiling in the photos?’
“Well sometimes it’s very hard to smile.
“They don’t know what is going on in the background.”
She added: “I have the privilege of having this life, but I miss my family and friends in South Africa and I’m often sad because I cannot always be there for them.”
Source: EXPRESS CO UK