Prince Harry's dad has been questioned for over 36 years, rumors saying that Prince Charles isn't his birth father. 

Many rumors are persistent in saying that the Duke of Sussex's biological dad is Princess Diana's lover, James Hewitt.

James reportedly started his affair with Princess Diana after being tasked to give her riding lessons. He was a cavalry officer, and despite the rumors, he has consistently trashed the claims.

People are still commenting about the entire thing, however, that now, the late Princess' closest friend, Sarah "Fergie" Ferguson, is determined to put the rumors behind once and for all. 

An insider reportedly told New Idea that the Duchess of York is "nothing short of exasperated that this story crops up every few years." 

"It frustrates her to let this go on, which is why she broke ranks. She's sick of hearing it."

As a close friend of the late Princess of Wales, the 61-year-old would've had some insights on what's going on with the mother-of-two. 

The insider added, "They had their tiffs over the years, but Fergie was one of the few people Diana could turn to with delicate matters."

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Though Fergie promised to take some of Princess Diana's secrets to her grave, Prince Harry, not being Prince Charles' child, is reportedly just not one of them. 

The Duchess is also worried and bothered how the British royal family remains silent about the entire thing despite it being a nasty rumor. 

Per the insider, the said rumor is "the last thing they all need right now, especially Charles."

Now, Sarah Ferguson is reportedly determined to finally go public with what she knows, arguing that the facts, even the timelines, can speak clearly for themselves. 

The insider explained that James and Princess Diana hadn't met each other when Prince Harry was conceived in 1984. 

"It's chronologically impossible for [Hewitt] to be the father. It's all a silly conspiracy theory and she's absolutely fed up with it."

So the answer to who the Duke of Sussex's dad is? "There's absolutely no question that Charles is Harry's father," per the source. 

Recently, the Duchess also felt saddened by the thought of not being grandparents to their children's kids. 

She told Bella magazine of Princess Diana, "We'd be having granny parties together and having a great time."

Princess Diana passed away on Aug. 31, 1997, after succumbing to the injuries she sustained from a car crash in Paris, France.

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Tags: sarah ferguson duchess of york Prince Harry Prince Charles Princess Diana