Former child star Hayley Mills is opening up about the heartbreaking financial loss that followed her wildly successful years with The Walt Disney Company — revealing that most of the money she earned as a young actress disappeared because of taxes and poor legal advice.

Mills, best known for starring in Disney classics like “The Parent Trap” and “Pollyanna,” recently reflected on the situation while appearing on “The Rosebud Podcast” alongside her sister, Juliet Mills, in celebration of her 80th birthday.

When podcast host Gyles Brandreth asked what happened to “the millions” she earned during her Disney career, Mills bluntly replied, “I gave it to the tax man.”

“It was rather a big chunk,” she said. “It was most of it because it was all put into a trust fund, because super tax was 90% in those days, so they had to do something.”

Mills explained that the trust fund created to protect her earnings ultimately backfired after British tax authorities challenged the arrangement. She said the family solicitor, Stanley Passmore, badly mishandled the situation.

“Stanley also advised Daddy, and not very well,” Mills said, referring to her father, acclaimed British actor John Mills. “The trust company was set up for me.”

According to Mills, things came crashing down when she turned 21 and expected to receive access to her money.

“Instead of being given the key to the door, I was handed an envelope across a green baize tablecloth,” she recalled. “The Inland Revenue basically saying, ‘Thank you. You owe us 90% of your earnings.’”

Mills admitted she struggled to fully understand what was happening at the time.

“I said, ‘Well, what does this mean? I don’t understand,’” she shared. “And Stanley laughed and said, ‘Well, I think it means you have to move to America [for work].’”

She then added sharply, “He was a crook. He didn’t give a flying Dutchman.”

Reports from The Times of London later revealed that Mills fought the case for years and even briefly won a legal victory when Judge Lord Denning ruled in her favor during the 1970s. However, the decision was later overturned by the House of Lords, leaving Mills responsible for the enormous tax bill.

If she had ultimately won the case, Mills said she could have kept roughly 2 million pounds — an amount worth more than $17 million today.

Despite the painful financial setback, Mills said she still considers herself fortunate compared to many former child stars.

Back in 2021, she told Fox News Digital that she benefited from having supportive parents and working under Walt Disney himself.

“I was working for a studio with a boss who was a genuinely good man,” Mills said. “He cared about the people who worked for him.”

She also reflected warmly on her friendship with Walt Disney, calling him “a very warm, kind and sweet man.”

“I always knew he was a brilliant, wonderful, amazing man,” Mills said in a previously reshared interview. “And how amazing is that, to be taken around Disneyland by Walt Disney?”