Elton John's guitarist Davey Johnstone is in discussion with Netflix about a new documentary which will include material left out of the movie Rocketman.

According to The Sun, the documentary The Pillars of Hercules (inspired by Elton’s middle name, Hercules), will concentrate mostly on the '70s and is set to include previously unseen backstage footage of the singer with the late John Lennon.

Johnstone has been compiling the documentary for years and is reportedly discussing a deal with Netflix.

He postponed the project for six years to avoid clashing with the Rocketman biopic and Elton’s Farewell Yellow Brick Road tour. It appears the musician did not want fans to be inundated with new content in a crowded Elton marketplace.

"It was entirely right that I should do that as I did not want to get in the way of those projects,’’ Johnstone told the Greatest Music of All Time podcast. "If it is too diluted then nothing does well."