It's something that AC/DC fans have been expecting for a while, particularly since he dropped a major hint that he would be 'backing off touring and recording' with the band earlier this summer - but Cliff Williams has officially left the Australian rock band.

The long-time bassist (66), who had played with AC/DC since 1977, said in a video message posted to the band's account that it was time to call it a day. His last gig with the band was last night in Philadelphia, the last night of their 'Rock or Bust' world tour.

"It's time for me to step out, that's all," he said. "Not because we've lost Mal [Young, Phil [Rudd] or Brian [Johnson] - everything changes when something happens like that. When Bon [Scott] died, it changed. Everything changes.

"I'm just ready to get off the road and do what I do. In between tours, we take a few years off. So I know how to do that, and I know what I'm going to do. Again, t's just my time. I'm happy - family time now. Chill out and not do this."

He added: "I couldn't have asked for anything more, being in this band and playing this music."

Williams's departure means that the only remaining original member of AC/DC is now guitarist Angus Young.

Watch his message here (click image to play):