King Charles and Camilla stopover in India for private visit to Soukya International Holistic Health Centre

King Charles and his wife Queen Camilla have made a secret stopover in India following their recent tour of Australia.

The monarch, 75, who has been battling an undisclosed form of cancer since February, had medics on standby 24 hours a day during his nine-day trip earlier this month.

The visit to Australia marked the first by a reigning British monarch in 13 years - and required Charles to pause his chemotherapy treatment until his return home.

Their Majesties visited Sydney and Canberra before flying on to Samoa for the Commonwealth Heads of Government Meeting (CHOGM) and it’s since been revealed they made another stop on their way home.

The couple landed in southern India last Sunday for a private four-day visit to the Soukya International Holistic Health Centre in Bengaluru, Indian media reported.

The resort specialises in alternative medicine including ayurveda, homeopathy, yoga, and naturopathy, and claims to focus on health promotion, early intervention and the treatment of illness - including cancer rehabilitation.

Both Charles and Camilla have visited the centre several times before.

However, understood the visit was not connected to Charles’ cancer treatment, instead, his doctors had advised the monarch to include appropriate periods of rest following long travel days throughout the tour.

A Buckingham Palace spokesperson told 7NEWS on Wednesday: “Their Majesties had a short private stopover in India to help break the long journey back from Samoa.”

“They return to the UK this morning.”

His cancer treatment will resume on his return to Britain, as planned.

Buckingham Palace said in April that Charles was “greatly encouraged” by news from his doctors he could resume public duties while his treatment continued. Despite the encouraging signs, a planned visit to New Zealand was dropped from the tour.

- with AAP