Prince Charles has a secret nickname for his daughter in law Meghan Markle and according to a Royal expert, it is a compliment.

According to reports, the Prince of Wales has a secret code name for the Duchess of Sussex.

According to royal commentator Christine-Marie Liwag Dixon, the name shows that Charles has a “lot of respect” for Prince Harry's wife.

Christine told viewers on The List: “Meghan Markle hasn't had an easy time of it since joining the Royal Family.

"Not only has the press hounded her relentless, but she has also said that she felt less than at home in the Royal Family.

“The Royal Family may not have approved of Meghan and Harry stepping down as senior royals despite them doing so to escape an environment that was clearly not good for their mental health."

She added: "However it seems that Prince Charles had a lot of respect for Meghan's resilient nature.

 “This was evident in the secret nickname he reportedly had for her: 'Tungsten'.

"As royal correspondent Russell Myers revealed on Lorraine in 2019, Charles nicknamed her after the metal as 'she is tough and unbending'.

"Tungsten is the strongest naturally occurring metal on the planet.

"That makes this a pretty neat compliment all things considered."

Harry and Meghan are expecting a baby girl in the summer as they enjoy a new life in the US.