The Met could not confirm the bodyguard had quit because they said they do not comment on anyone involved in the bodyguard role.
The police officer, who has never been named for security reasons, was pictured leaping into action when Meghan abruptly left a market in Fiji during the royal tour of Australia and the Pacific last October.
The bodyguard, who is thought to hold the rank of inspector, had replaced Sgt Bill Renshaw, Harry's long-standing head of security, who retired after more than 30 years in the force.
She's leaving just weeks before Meghan and Harry move out of their London home and Relocate to Frogmore Cottage in Windsor to raise their first child. The news comes after the departure of Meghan's personal assistant, Melissa, late past year.
Rumours of a royal feud have been circulated for the last couple of months.
"Unlike someone who has grown up in the Royal Family and has been used to having close protection from an early age, it can be constraining", a source reportedly told the outlet.
The couple's Australian private secretary Samantha Cohen was the first to jump ship when she announced she was going in November. Royal biographer Robert Jobson claimed in his book, Charles at Seventy, that a stressed-out Harry became "short-tempered" with staff and insisted: "What Meghan wants, she gets".
It is rumoured that Meghan even changed the entire contents of his fridge to make sure it now includes hummus, carrots, green juice, almonds and chia seed pudding, foods Meghan can apparently not go without.