King Charles' cousin has slammed the British royal family's alleged treatment of Meghan Markle

King Charles' third cousin has slammed the British Royal Family for their alleged treatment of Meghan Markle.

She claims partners of Royal members often cop incredible scrutiny and only the ones who are 'tough as nails' manage to stick around.

However, she has been particularly shocked by the alleged treatment of Meghan Markle since she started dating Prince Harry.

She told The Post: "To Meghan Markle, I say, ‘What you are going through is a hellish kind of hazing'.

“If she can just hang in there, someone else will come along who can take the heat. Nobody gets a pass.”

Ms Oxenberg said Meghan is one of many who have gone through the gauntlet of the British Royal Family's approval process.

She alleged that even Catherine, the new Princess of Wales, copped some mocking when she landed on the scene.

Christina said Meghan's treatment is similar to when Prince Michael of Kent, who is a first cousin of the late Queen Elizabeth II, married Baroness Marie-Christine von Reibnitz in 1978.

“She was treated the same way Meghan [has been] treated — with this mocking and lack of respect,” she said to The New York Post.

“We always used to mock her because she kept referring to the royals as ‘delicious cousins.’

"[The hazing] was all done out of habit and not full of hatred and violent plotting. I was a witness.”

Christina says her mother, Princess Elizabeth of Yugoslavia, was quite close to her second cousin, King Charles, when they were younger.

She explained how the British Royal Family can be brutal when a member brings in a partner and she believes that is evident with Meghan Markle.

“They are tough, they are tough on foreigners. It’s not about your skin colour, it’s about being a foreigner," she said.

However, she's called on everyone to go easy on the Duchess of Sussex.

Ms Oxenberg said: “She is Harry’s choice of wife. By their own metrics they have called it a class system. They came up with that system, [by which] you have to respect Harry’s choice.”