Unseen colour footage of David Attenborough's Zoo Quest series unearthed from BBC archive

To the amazement of everyone – including Attenborough himself – the film was found to have been originally shot in colour, even though with television still very much a monochrome medium it was broadcast in black and white.

“I was astonished,” says Attenborough today. “I had never seen it and, indeed, nobody had ever seen it. I said 'it’s impossible – we shot in black and white'.”

For once the legendary broadcaster was wrong and the newly uncovered colour footage will be shown for the first time next month as part of a tranche of programmes being broadcast to celebrate his 90th birthday.

His long-time friend and filmmaking collaborator Miles Barton had the job of putting the 90-minute Zoo Quest in Colour together. He recalls the moment he told Attenborough of the discovery.

“I rang him up and said 'we’ve got this colour footage from the first Zoo Quests' and he said ‘I don’t believe it. Zoo Quest was not shot on colour footage’. He was quite adamant. So we transferred some of the material onto a DVD and bunged it in the post and he was amazed.”

Barton says producing this new documentary has been a real labour of love.

“Zoo Quest was the series that established David as a natural history broadcaster so this feels like seriously important material. It shows him and the subjects he was filming in a light we have never seen before.”

Barton says the canisters of film, simply marked “Attenborough”, were discovered last autumn in the library of the BBC’s Natural History Unit in Bristol.

“I have been here 30 years and I didn’t know about them,” he says. “The most experienced archive researcher who’s also been here 30 years didn’t know about them. They was uncatalogued and unlabelled. I find it unbelievable myself. I was totally amazed.”

When the news reached London, a further search revealed more of the original colour rushes – all from the first three expeditions Attenborough undertook for Zoo Quest in 1954, 1955 and 1956 – making six hours of unseen material in total.

So why, if it was known that the footage could only be broadcast in black and white, was colour film used?

The reason gives us a glimpse into the feisty nature of the ambitious young Attenborough, then aged only 28. Against all established BBC practice he wanted to take lightweight, hand-held cameras shooting 16mm film on location, first to Sierra Leone, then Guiana and later Indonesia. It led him into conflict with the BBC. “The head of films thought that 16mm was beneath contempt,” recalls Attenborough in the new film. “We were rebels really and rather sneered at by film departments.”

As Barton explains, a compromise was hammered out.

“The agreement was that they used this colour film stock because even when broadcast in black and white it gave a better look than conventional black and white film. Though they couldn’t use it in low light and so they had to revert to black and white stock for that.”

Today, the rescued colour film retains a remarkable quality. “I was absolutely astounded by it,” says Barton. “It looks like colour film from the 90s. The amount of cleaning up we had to do was really very small – 90 per cent of it is exactly as it was originally filmed.”

So how does a young Attenborough shape up in colour? Well we see plenty of him in action. There are scenes of him stripped to his waist and wading through a swamp to capture a juvenile crocodile, swimming in a jungle river and chasing an ant-eater: remember the object then was not just to film animals in the wild but to capture them and bring them back to London Zoo.

“He just looks so energetic and youthful,” says Barton. “There is something about the colour footage that really brings him to life. Who would have thought that at this stage of his life and career there would be something new to say about David? It just feels like a real treat.”

There was, though, a bittersweet postscript to the story. David Attenborough was never meant to be the presenter of Zoo Quest – that task should have fallen to Jack Lester, head of the reptile house at London Zoo and part of the expedition team. But he was taken ill before the first series aired and so Attenborough stepped into his shoes… and the rest is history.