Queen Camilla gives four-word health update on King Charles in rare TV appearance

has revealed the King "is doing really well" as he continues to undergo treatment for an undisclosed form of cancer before joking: "The problem is trying to stop him."

Camilla, 77, was speaking on a new documentary on domestic violence when Diana Parkes, whose daughter, Joanna Simpson, was killed by her estranged husband in 2010, asked after her husband.

"He's doing really well," Camilla said, prompting Ms Parkes to add: "He looks amazing. He looks amazing. I'm so pleased."

The Queen, who has made no secret of her desire for the King to slow down, responded: "The problem is trying to stop him. That's the problem."

The royal couple have recently returned from a 10-day trip to Australia and Samoa where the couple packed in 36 engagements between them.

Charles, 75, who paused his cancer treatment for the state visits, is said to have found the long-haul trip "the perfect tonic" as he "thrived" on the busy schedule.

"He has genuinely loved this tour. He has genuinely thrived on the programme. It's lifted his spirits, his mood and his recovery. In that sense, the tour - despite its demands - has been the perfect tonic," a senior Buckingham Palace official said.

Next year, the King is expected to return to a "normal" schedule of overseas trips, with visits in the spring and autumn of 2025, subject to his doctors' approval.

Italy and Canada have been mooted as potential destinations.

The King and Queen enjoyed a visit to an exclusive £3,000-a-week resort in Bangalore, India, on their way back from Samoa.

They spent three days at the Soukya International Holistic Health Centre to help break up the long journey back to London.

The wellness retreat is described as "a holistic health destination to restore your body's natural balance of mind, body and spirit" on its website.

Now they are back in the UK, the King has resumed his cancer treatment and will return to a normal schedule of engagements this week.

Her Majesty The Queen: Behind Closed Doors will be shown on ITV1, ITVX, STV and STV Player on November 11.