Campaigners have called for Charles and William to be blocked from taking millions of pounds a year from estates of people who die without a will or next of kin.

The system, known as bona vacantia, means that anyone living on Duchy of Lancaster land who dies without a will or next of kin has their estate and assets seized by the Duchy.

The Guardian has reported that Charles - who took over the Duchy of Lancaster when he became king - is using the money to upgrade his property empire.

Speaking for campaign group Republic, Graham Smith said today:

"Raiding the pockets of the dead is obscene and the system needs to be scrapped."

"This arrangement amounts to a royal death tax, not to spend on public services but to spend on the luxury lifestyles of our head of state and his son."

"As with everyone else in the UK, if you die without a will or next of kin your estate should be used for the public good, not handed over to a couple of billionaires."

"The Duchies are Crown property, which mean they belong to the nation. The simplest solution would be to take the Duchies back under public control and put all their profits to public use."

"Through the Duchy of Lancaster we pay Charles an income of more than £22m a year, on top of the hundreds of millions spent by the government on palaces, parades and travel."

"It's time to push back and to tell Charles and William enough is enough. Stop digging your hands deeper into peoples pockets."

The Duchy of Cornwall, which now hands its profits to William, and the Duchy of Lancaster, are Crown properties which were previously part of the Crown lands which later became the Crown Estate. The historic record is quite clear that they are public assets, not private estates.