The King is under pressure to reimburse the cash-strapped NHS after it emerged he was charging a trust at least £11.4million in rent to stock a fleet of electric ambulances.

An investigation has revealed that the private estates of King Charles and Prince William earned millions of pounds for the NHS, armed forces and charities.

Land and properties owned by the Duchies of Lancaster and Cornwall are also leased to schools, mining companies and large businesses, among others.

The inquest heard that the Duchy of Lancaster, on behalf of the King, struck a deal with a London trust which will see the NHS pay more than £11 million over 15 years for the right to park ambulances in one of its warehouses.

Documents show the duchy earns £830,000 a year renting the two-storey warehouse from Guy’s and St Thomas’ NHS Foundation Trust in London.

Dennis Reed, of older people’s campaign group Silver Voices, told the Mail: “I think it’s actually shameful, given the NHS is under so much pressure, that the royal family is charging for parking for ambulances and other NHS uses.

The estates have helped make the British royal family one of the richest in the world, generating almost £50 million for the King and Prince of Wales in the last year alone.

The Duchy of Cornwall, led by Prince William, states that “it is not a public body nor is it funded by taxpayers.”

“(It) looks more like a money-grabbing activity.

“And I hope that because of the publicity, there will be an overhaul within the Royal Household.”

The astonishing results show:

• The duchies have struck deals worth at least £50 million with public services such as the NHS, state schools and the armed forces;

• The Ministry of Justice is paying £37.5 million over 25 years to use Dartmoor prison, currently empty because of radon;

• Charles and William earned at least £22 million in rent from charities over 19 years – sometimes by serving as their patrons;

• Homes rented by royal estates fail to meet government energy efficiency standards and leave tenants struggling with mold;

• Prince William, who travels to South Africa tomorrow for his Eco Earthshot Prize, has allowed controversial mining companies to drill on land in the Duchy of Cornwall.

The investigation by Channel 4’s Dispatches and the Sunday Times examined the land and properties owned by the two senior royals across the duchies.

She identified 5,410 landholdings, mineral rights and properties held by the Duchy of Lancaster, on behalf of the King, and the Duchy of Cornwall, for the Prince, then examined the commercial agreements and leases relating to these parcels.

He noted that duchies impose taxes for the right to cross rivers or dump waste there; unload the cargo on the shore; run cables under their beaches; operating lifeboats and even digging graves.

The King is under pressure to reimburse the cash-strapped NHS after it emerged he was charging a trust at least £11.4million in rent to stock a fleet of electric ambulances.

The total value of the duchy’s assets – a portfolio of land, properties and assets held in trust for the sovereign – increased by almost 3 per cent, from £533 million to £548 million. Part of the estate is the medieval Lancaster Castle (pictured)

The 18,433 hectare duchy estate, founded in the 13th century, constitutes a unique portfolio of land and assets across Lancashire, Yorkshire, Cheshire, Lincolnshire and Staffordshire. Another highlight is Tutbury Castle in Staffordshire (pictured)

The Duchy of Cornwall also receives rent for Dartmoor Prison, with the Ministry of Justice paying £37.5 million.

Charities have paid millions to rent a 1960s office building in London. They include Macmillan Cancer Support and Marie Curie Cancer Care, of which Charles is patron. The investigation also found that private residential properties rented by the two duchies do not meet minimum energy efficiency requirements.

A spokesperson for the Duchy of Lancaster said: “The day-to-day management of the portfolio is the responsibility of the Council and the executive team. » Buckingham Palace declined to comment.