Meghan Markle was celebrated for closing her own car door in September just like the plebeians, but royal security officers are against it for a serious practical reason: The Duchess of Sussex's safety.

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A new report claims that Markle, 37, has been warned by police not to close her car door behind her in case of an attack after she and Prince Harry allegedly faced threats from the far-right — because vehicles royals travel in have self-locking doors.

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"Meghan and Harry like to meet the public as much as possible and make contact with the crowds that come to see them. And although having a car door closed might seem like a trivial thing, it could be the difference [in life or death]," a source told The Sun on Sunday.

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"God forbid if anything did go wrong arriving at a royal engagement, but security need to be able to get them back into cars in seconds if needs be. If they're closed and locked, it's impossible."

A former royal protection officer also revealed to Hello! magazine why Markle and fellow duchess Kate Middleton are often seen without seatbelts: It's usually to avoid wrinkling their clothes.

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"What is significant about this event or situation? Is an individual's look and appearance important?" Simon Morgan said. "Protection is a very unique area of policing and there are a lot grey areas, but you are always judging each situation to weigh up the risks and threats with the outcomes you are trying to achieve."

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He added, "Sometimes royals aren't strapped in for their own safety, for example, if they might need to make a quick escape in an emergency."

A rep for Kensington Palace did not immediately return Fox News' request for comment on royal protocol.