It was one of the few times the band performed together since breaking up following the death of drummer John Bonham in 1980, and sparked frenzied speculation that a lucrative reunion tour could be on the cards.

That has failed to materialise, and at a news conference to promote the new video of the 2007 gig, called "Celebration Day", lead singer Robert Plant, guitarist Jimmy Page and bass/keyboard player John Paul Jones all refused to be drawn on future plans.

Asked whether they might consider reuniting, Page, considered one of the greatest guitarists in rock history, replied: "Can I ask you a question? You've all been to see the film. Did you enjoy it?"

From a mostly partisan crowd of journalists and fans, the answer was in the affirmative. "Then we've done our job," added the silver-haired 68-year-old.

When a reporter called out would Led Zeppelin "do it again", Plant simply replied: "With you?"

Their non-committal answers will mean the guessing game over one of the most eagerly awaited reunions in rock is likely to continue for some time to come.

"The concept of looking back and asking don't you wish you could do it again... the thing about what we were when we were really happening, when we were together and that was our sole purpose in creative life is that we were always creative." Plant said.

Celebration Day, directed by Dick Carruthers, is a two-hour film featuring all 16 tracks of the band's tribute gig, starting with "Good Times Bad Times", taking in "Dazed and Confused" and "Whole Lotta Love" and concluding with "Rock and Roll".

"What needs to be stressed here is that when we played the O2, the idea of playing the O2 wasn't to make a DVD or film or anything like that at all. It just so happened we had all of this material going on behind us and some very fine production and camera work that Dick Carruthers was doing," said Page.

When tickets went on sale, an estimated 20 million people applied for 18,000 places, underlining the level of pressure the band has come under to play together more regularly.

On drums in the place of Bonham was his son Jason, a musician in his own right, who was praised by Plant and Page.

The long-haired lead singer admitted he had been reluctant to perform Stairway to Heaven, one of Led Zeppelin's most popular tracks, and arguably its most obscure in terms of the meaning of the lyrics.

All three band members expressed a sense of relief when the O2 concert was over.

Jones, a man of few words when it comes to the press, was asked why Led Zeppelin had taken five years to produce a movie based on the concert.

"Five years is like five minutes in Zeppelin time," he said.

Plant talked about the live music he's interested in now: "I think Mumford and Sons excite me because they do construct and they do have a drama and they do have optimism and they can turn a crowd upside down which is fantastic and there's a lot of great DJ'ing stuff going on too."

American blues artists have long been an influence on the group's heritage.

"The references to those old players, to me, it's a kind of home of the heart. I really still feel moved by what their lives and worlds and aspirations might have been and it's untouchable really because they came from, like we do, they came from another time. And we come from another time, really now, as you saw us this morning. So the blues and rock and roll for me is still part of my...the pulse of my life," said Plant.

Celebration Day will be shown at select movie theatres on October 17 and is available in video and audio format on November 19.