Richard Branson, the Virgin Atlantic airline chief, lifted the lid on how he joined the mile-high club in a plane toilet, in interview extracts released Sunday.

The British entrepreneur said it was "every man's dream," adding that he had to wipe handprints off the toilet mirror following the high-flying high jinks.

The 57-year-old knight also admits to having tried cocaine, ecstasy and Viagra, in the forthcoming edition of GQ monthly men's magazine.

"I was sitting in economy on a Freddie Laker flight, next to this very attractive lady, as we headed to Los Angeles," said the boss of Virgin Atlantic.

"We got chatting and it went a bit further. And it was every man's dream, to be honest. I was about 19," the tycoon boasted.

"I remember getting off the plane and she turned to me and said, 'Look, it's slightly embarrassing but I am meeting my husband at arrivals, would you mind holding back a bit.' But it was a memorable flight.

"The problem with plane loos generally is that they are very small, and the acrobatics can't take too long because there's no room and people start banging on the door," Branson explained.

"What I remember vividly is seeing four handprints on the mirror as we finished, and thinking I'd better wipe them off."

Branson's Virgin airline has made no bones about using sex to sell seats. It has used slogans including "Hello gorgeous," "Love at first flight," "You never forget your first time," "More experience than the name suggests," and "Extra inches where it counts."

Speaking about his experiences with the virility drug Viagra, Branson said: "I had to tie something around my trousers for the rest of the next day to make sure nothing showed."

He admitted: "I took ecstasy once... but it didn't have a massive effect on me."

Of cocaine, he added: "I suspect I've tried it, yes."

And he said Keith Richards, the hell-raising Rolling Stones guitarist, was the "first person to teach me how to roll a joint.

"I haven't tried skunk (a strong variety of cannabis), I have smoked cannabis though. I went with my son on his gap year, for God's sake. We learnt to surf and had some nights where we laughed our heads off for eight hours."

The Virgin Group chairman joked he would be good at Tantric sex, "but I keep dropping the book."

Branson has combined canny business sense with a gift for self-promotion, and his goings-on have long fascinated British media.

Newspapers have recently linked the flamboyant businessman's daughter Holly with Prince William, who is second in line to the British throne.

But Branson insisted the pair were "just good friends" and his daughter marrying the prince would be "a dreadful idea."

He said: "Nothing against William, but the life the royals lead, and the responsibilities that go with it are very difficult."