Meghan Markle's estranged father, Thomas Markle, accused the Duke and Duchess of Sussex of destroying and cheapening the royal family.

In an interview for a documentary with Channel 5, the Duchess of Sussex's father described Prince Harry and Meghan Markle's behavior as "embarrassing."

"When they got married, they took an obligation, and the obligation is to be part of the royals and to represent the royals," Thomas Markle said before saying it would be "foolish for them not to."

He added that the British monarchy is "one of the greatest long-living institutions ever" and that the royal couple is "cheapening it" and "making it shabby."

According to Thomas, Harry and Meghan are "turning into lost souls" who are making the royal family look like "a Walmart with a crown on" -- referring to the discount supermarket giant.

Thomas then sent more hurtful messages to Meghan, emphasizing that how the former "Suits" actress behaves is not the way he raised her. 

Thomas also believes that Meghan was tossing away "every girl's dream."

"Every young girl wants to become a princess and she got that and now she's tossing that away... it looks like she's tossing that away for money," the 75-year-old Markle patriarch said.

The Duchess' dad went as far as to say that Meghan is tossing everything away, referring to their renovated Frogmore Cottage where the couple spent $3 million and then promised to pay back the taxpayers' money.

"Apparently, $3 million and a 26-room home isn't enough for them. It is embarrassing to me," he said.

Thomas was filmed at his home in Mexico for the documentary. He was once close to his daughter when she was growing up and even paid for her university tuition.

Nonetheless, their relationship has broken down irrevocably in recent years. In fact, their relationship has been really bad that he could even testify against Meghan in the legal battle with the Mail on Sunday.

The Mail on Sunday has already submitted its defense to court action by Meghan over the publication of the letter sent to her father.

Thomas admitted that he is not expecting Prince Harry or Meghan to contact him, especially now. He also revealed that he does not know what the couple is looking for or if the couple actually know what they are looking for.

Not only is Thomas Markle criticizing his blood-relative, even half-sister Samantha Markle has something to say about Meghan as well.

"From my perception, I feel she did enjoy it when there was the fab four and the photographs of her hair blowing in the wind and the smiling and the contrived British accent," Samantha said. "But when the public start to criticize her behavior and expenditure, the tune changed and it became a bit more attribution error, avoiding accountability, flipping the script."

The interview was filmed after Prince Harry and Meghan's announcement that they would step down as senior members of the royal family.

The 90-minute documentary entitled "Thomas Markle: My Story" will talk about the "complicated" relationship with his daughter and their dramatic fallout.

The Markles' intervention in the monarchy's worst crisis this generation came as the Queen finalized a deal for the Prince Harry and Meghan Markle who are leaving Britain to seek financial independence, according to the Daily Mail.

It is expected to air soon, though a final date has not been confirmed.

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