The couple, thought to be aged about 17, managed to get a pod to themselves and were caught on CCTV cameras locked in an embrace 450ft above the Thames.

It was only a matter of time before something of this nature happened

BA spokeswoman Kelly Matthews

British Airways, sponsors of the �35m tourist attraction, confirmed something of a "romantic nature" did happen in the millennium wheel on Sunday evening.

"We have CCTV cameras in each pod but the quality of the pictures wouldn't be good enough to make out just how intimate the couple actually got," said spokeswoman Kelly Matthews.

Wheel of fortune

"The only two people who will ever know exactly what did and didn't happen on the wheel are the two people involved.

Around 10,000 people take a ride in the wheel each day

"But it was visible on the cameras that a certain amount of kissing and cuddling was taking place. And they did make a pretty sharp exit after the ride was finished."

The daring pair's luck held out as Ms Matthews said there was no way of tracing them from the 10,000 people who take the half-hour ride on the wheel every day.

Mile high smiles

"So far the wheel has had about three million visitors and to be honest it was only a matter of time before something of this nature happened, though we don't want to encourage it," she said.

"If we do see this kind of activity, which may cause offence, naturally we will intervene if appropriate."

Ms Matthews said she rang British Airways to tell them about the incident.

"They just said 'Welcome to our world, the Mile High Club's been happening for years!'"