But the trip could see Harry separated from his family for weeks because of current lockdown rules.
“Rumour also has it that Harry landed into the UK last weekend on a private jet,” claims the insider.
“There has certainly been a flurry of activity around Frogmore, where he would be undergoing mandatory quarantine for 14 days. I’ve heard he came in without Meghan and Archie, as he didn’t want them to travel at such a dangerous time.”
It is understood Harry most likely wanted to reconnect with members of the royal family during his stay and make an attempt to mend his relationship with his father and brother.
News of Harry’s surprise visit comes just days after Prince Charles and Prince William shared a candid photograph of the two of them together to celebrate Father’s Day, which was celebrated in the UK on June 21.
Glaringly absent from the touching social media tribute was any mention of Harry.
Royals author, Phil Dampier, tells New Idea that this photo would have greatly affected the absent prince.
“Harry would have seen the picture and it must have made him think about what he has done and what he is missing.
“It’s a powerful contrast, and the picture demonstrates the importance of family ties. With Charles resting on William’s shoulder, the message is that he’s going to support and look after his father in the future, come what may.”
Meanwhile, another royal author, Deb Stratas, has come forward to air her concerns.
The royals expert, who penned a historical fiction trilogy based on Diana’s life, speculates that William and Harry’s mother would have been “devastated” to witness her boys barely on speaking terms.
Deb also believes the princess would have been saddened by Harry’s recent decision to step down as a senior royal and move abroad.
“She would’ve been disappointed in Harry because she really tried to raise him to be a support to William.
“She saw Harry as second in command. Diana had a strong sense of duty.”
But, as evidenced by Harry’s secret trip to the UK, it appears his and Meghan’s decision to step away from royal life began long before anyone realised.
“His trip suggests he has a green card, otherwise he wouldn’t be allowed back in, because the US has banned incoming passengers from the UK unless they are green card holders or citizens,” explains the insider.
“He would have applied for that almost two years ago.”
Deb also believes Diana would have raised a warning over Harry and Meghan’s decision to move to LA.
“She would’ve advised caution about them going down the Hollywood route as it’s quite fickle. They love you one day, tear you down the next!”
Meanwhile, the royal family are no doubt still hoping Harry’s flying visit could lead to a more permanent return.
“They all wish Harry was back for good,” says the insider. “But the fact his wife and child are by all accounts still in LA, this is looking unlikely.”
For more, pick up a copy of New Idea, on sale now.