A ZIMBABWEAN man could lose a dream job as an officer of the British Queen’s Cavalry after a newspaper claimed he was “an internet pervert who hosts orgies in his royal barracks flat”.

By day Captain Tari Mundawarara proudly leads the Changing of the Guard as hundreds of tourists watch on Horse Guards parade.

But at night the soldier - who trained with Prince Harry - trawls sex sites, offering girls behind-the-scenes royal tours as bait, the News of the World reported.

Bragging that he's part of the Queen's bodyguard, seedy Mundawarara's chat-up line is: "How would you like to get f***** by a cavalryman in a royal guardroom?"

He's also prepared to INSULT the Queen - joking that she's "definitely not totally with it" - and BREACH SECURITY, giving away secret details of her movements to lure women, the paper reported on Sunday.

Mundawarara was caught off-Guard after Britain’s biggest-selling newspaper “received a tip-off about his activities on the internet from a site user”.

He had boasted to her: "I'm an attractive well built and sexy professional black male, 32 years old and good in bed. I'm open to the idea of playing with couples . . . if you're lucky I might wear my uniform."

Disloyal ... Mundawarara said to have dismissed the Queen as "not totally with it"

Mundawarara sent snaps of himself in Life Guards uniform -- including one on his horse -- to impress her before offering her sex in the royal guardroom.

Then he asked the girl to bring along another blonde friend for a threesome. "I have not had two blondes before. I've had a brunette and a blonde," he bragged.

He said he had to have his romps where he worked so he could be on call "in case the Queen comes".

He arranged a meeting with the News of the World’s undercover reporters, posing as swingers, in the Clarence pub in Whitehall on Wednesday last week after his last parade.

Downing white wine, the polo-playing Zimbabwean mouthed off about his royal duties with the Household Cavalry.

"We are the Queen's bodyguards. We're going to Windsor next week because the President of India is coming," he said. "We'll pick up the Queen and whoever it is and take them to Buckingham Palace."

"She's in the Palace today and she's going to Windsor on Friday," Mundawarara added, leaking her itinerary. The disloyal guardsman then gave his verdict on his employer: "She's definitely doddery [mentally or physically infirm with age] - definitely not totally with it."

He told the couple he trained to command tanks alongside Prince Harry three years ago -- and said he even warned him to curb his drinking because driving a tank "is not so easy with a hangover".

Mundawarara then led the News of the World’s undercover reporters through the famous Horse Guards arch towards his flat in an imposing building. "You see the top floor, that's my bedroom," boasted Mundawarara.

The officer also took the reporters to the stables where he posed with his horse, York.

Before long they reached the front door of his flat which carried a gold plaque saying Captain The Queen's Life Guard. Inside the walls were adorned with paintings of horses and officers.

Mundawarara took the couple into his bedroom where his red tunic was on a stand beside his riding boots and near his white plumed helmet. But before the action could begin, the reporters made their excuses and left.

A Buckingham Palace spokesman said: "We will investigate any issues relating to the security of The Queen."