A private hospital favoured by the royal family is to expand its facilities after receiving a grant worth up to £30m.

King Edward VII’s Hospital admitted the Duke of Edinburgh for five days last year over a bladder infection and treated the Duchess of Cambridge during her pregnancy.

Hospital chairman of governors Robin Broadhurst said the donation from businessman Michael Uren was “the most generous gift the hospital had ever received”.

He said: “We are all extremely grateful to the Michael Uren Foundation for securing the long-term and independent future of the hospital.”

Mr Uren, who served in the Royal Navy during the Second World War, worked as a civil engineer before founding Civil & Marine Ltd in 1955 - a shipping and cement company he sold in 2006 for a reported £245m.

His Michael Uren Foundation has given the hospital £5m and pledged another £25m over the next 10 years if it is needed.

King Edward VII’s treats paying patients and those with health insurance but offers means-tested grants to all former and serving armed forces members of any rank.

The hospital, which was founded in 1899 at the suggestion of the then-Prince of Wales, has treated most senior members of the Royal Family, including the Prince of Wales and the Duke of Cambridge.

The late Queen Mother went there in 1982 after a fish bone became lodged in her throat, and later had two successful hip replacements, while the Queen underwent keyhole surgery to remove a torn cartilage from her knee in 2003.

But it was also the workplace of Jacintha Saldanha, the nurse who took her own life after answering a phone call from two Australian DJs imitating the Queen and the Prince of Wales.

Saldanha had worked in Britain for 10 years but was found dead in her quarters at the hospital, which now runs a memorial fund for her family.

The hospital says it will use the gift to build additional operating theatres, consulting rooms, and new wards.

Chief executive John Lofthouse said: “This gift will enable us to reinforce oru position as one of the world’s most outstanding hospitals.”

Mr Uren said: “King Edward VII’s Hospital is very dear to my heart and I wanted to do all I could to ensure it has a long, successful, and independent future. I hope this gift will secure that outcome.”