The Beatles' last ever live performance, up on the rooftop of 3 Savile Row, is a legendary moment in music history and an event that Peter Jackson's new three-part Disney documentary charts.

Based on around 56 hours of film that for 50 years remained hidden within Apple's vaults, the series also gives an in-depth insight into the recording sessions for their album Let It Be.

Having mused over where they'd first perform some of the tracks, the band joke about being arrested. In the footage, Paul McCartney says: "We should do the show in a place we're not allowed to do it, getting forcibly ejected."

But, a young policeman who was there that day, has told Sky News the rooftop gig wasn't halted because nobody "knew what to do".

Ken Wharfe was 21 at the time. He'd been on traffic duty when he received a call from his "grumpy old sergeant" asking if he could hear a "dreadful noise".

"We walked up Regent Street and suddenly it became clear I could hear the music Get Back just sort of flowing over the rooftops of Soho."

When he arrived on Savile Row, there was a party atmosphere in the street.

Mr Wharfe said: "I remember thinking I needed a piece of this action, so I literally went into number three and ascended the stairs. I remember…Ringo Starr in that sort of tangerine coat and I thought 'this is the best thing that's ever going to happen to me in the police service'.

"None of us really knew what to do….because there wasn't a problem, there wasn't a crime, at worst it was noise but it was a pleasant noise."

While the band might have expressed a desire to be dragged off stage by police, Mr Wharfe says he and his colleagues were too busy enjoying the best seats in the house.

"I think that one or two of my colleagues, you know, had to make a stand but the bulk of us, we were more interested in actually getting a better viewpoint and listening!

"It was the last concert that The Beatles ever performed so, of all the things that I did in my career, I have to say this is the one thing that I remember more than anything else because it was just an amazing occasion."

In Beatles mythology, so it goes that the Let It Be recording sessions were fractious and unpleasant.

However, the new footage shows it wasn't anywhere near as miserable as we'd been led to believe as the band can be seen laughing and enjoying making music.

Sky News has spoken to one of the band's sound engineers, Dave Harries, who was also there that day having helped them record the album.

"They were so good, so talented," he says. "Their harmonies, you know, all the harmonies were brilliant."

Mr Harries believes the only real conflict stemmed from the boys' frustration at the recording process.

"They weren't very happy with the fact that the studio wasn't completed and running properly…that was a shame because they deserved better."

The documentary is a compelling insight and one that finally allows every Beatles fan the ending they'd always wanted - four young friends who might be ready to go their separate ways but who aren't at each other's throats but who are laughing and enjoying making music together.