"There is a great deal of hurt given that the Prince of Wales has gone out of his way to help his son who he loves dearly and embrace his daughter-in-law into the family,” the source told the publication.
The royal insider went on to say that the figures quoted on the Sussex website are not accurate as they don’t take travel into consideration.
The insider continued: "Also talk of what the Prince of Wales only pays towards both his sons from the profits of the Duchy is simply not true. He has paid out considerable sums from his private investments and money too.
"These are not small sums. It should not be a surprise that he is upset by all this given the truth about how he has supported his son,” the source concluded.
News of Charles’ apparent cash handouts comes after a new poll revealed that some British people think Harry and Meghan should even be evicted from their home.
According to the Mail Online poll, which was conducted by JL Partners, 60 per cent of the British public believe Harry and Meghan shouldn't be allowed to continue living at Frogmore Cottage.
What’s more, 60 per cent of people also believe that the Duke and Duchess should be made to repay the £2.4million (approx. $4.5 million AUD) they spent on refurbishing the cottage.
The poll also showed that 76 per cent of the general public think Harry and Meghan should no longer be financially supported with taxpayer money.
Likewise, 64 per cent of those surveyed believe the Duke and Duchess should not be allowed to keep any royal/taxpayer money, which is reserved for overseas trips.