The Duchess and Duke of Cambridge Kate Middleton and William were spotted hitching a free helicopter ride from a friend who was flying past their home in North Wales.

Will and Kate were accompanied by their dog Lupo as they made the 200 mile flight that dropped them off at aerodrome on the outskirts of London, according to the Daily Mail.

Their arrival was photographed by a couple who did not recognize the royal pair until they reached home. The couple was simply watching light aircraft taking off and landing at Denham in south Bucks.

They said: "We had no idea it was the royal couple at the time.

"We had a look at the photos on our laptop a few days later and realized that it was in fact Prince William and Kate.

"It's amazing to think that we saw the royal couple without any crowds around them.

"They were like any other couple out with their dog - albeit having just been flown in by helicopter.

"Lupo was very well behaved. Kate let him down on to the grass and he stayed close, although you could see he was excited."

Both the Duchess and Prince were dressed down, Kate wore jeans and flaunted her baby bump not bothering to button her jacket while William wore a sweater and jeans.

[To see photos of the Duke and Duchess of Cambridge Will and Kate on their helicopter journey click HERE]

When the royal couple arrived the Duke drove off in a Range Rover while his wife, who is due to give birth to their first child next month, left in a separate car.

According to the Daily Mail, Mr. Oliphant Hope, 49, said, "I know the couple and occasionally, when I am routing past North Wales, I give them a lift if it is convenient to all parties."

A Royal source said that, "The flight wasn't paid for and the helicopter wasn't chartered. There was no cost. It was a gift, a lift from a friend."

For more Kate Middleton news click HERE.