Actually Charles is his Dad, NOT Hewitt. Have a look at a picture of Charles Spencer and Harry-there is your answer. He is the image of Charles Spencer, Diana brother and Harry Uncle
When Diana fell pregnant with Harry she hadn't even met him at that time. Here is an article on it:
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The day Charles told Harry that Hewitt was not his father: It was the hardest conversation of his life... but the Prince had to end the cruel gossip
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Warm-hearted, brave, but also recklessly impulsive, Prince Harry is as complex as he is charismatic.
Here, in part three of a compelling new biography, we show how he idolised the soldier who many unfairly whispered was his true father...
Over dry martinis at Sandringham — mixed to the servants’ special recipe — there was just one question on the Royal Family’s lips: ‘Where’s Harry?’
When someone joked: ‘He’s confined to barracks — he’s been a naughty boy’, the Queen smiled. Only she, and a tiny number of the family, were in on the secret.
The truth was that while Her Majesty and her guests were beginning their Christmas celebrations in 2007, 2nd Lieutenant Wales was more than 3,500 miles away in southern Helmand, war-torn Afghanistan’s most dangerous province.
Even as his relatives were plumping up the pillows on their four-poster beds Harry — the first senior royal to fight on a battlefield since Queen Victoria’s grandson Maurice in World War I — was surveying the tiny, cell-like room at Forward Operating Base Delhi that was his temporary home.
To read the rest of it: The part about Charles conversation with Harry over the cruel gossip is about a third of the way down, if you don't want read it all.
Cont: http://www.dailymail.co.uk/femail/article-2306021/The-day-Prince-Charles-told-Harry-James-Hewitt-father-end-cruel-gossip.html
