A third series of 'Planet Earth' is reportedly in the works but it may not air until 2026.

Sir David Attenborough

Sir David Attenborough

The popular BBC nature programme returned with its second series last year to critical acclaim and producers are said to be working on a new series but it may not appear on screens until much loved host Sir David Attenborough is 101-years-old.

A producer said: "It's more of a team effort than any other genre. We're going off for three years around the world to film in really difficult places. They give their heart and soul to film these behaviours that are so hard to capture. Quite often we come back with nothing.

"We have a filming ratio that means every 400 minutes of film, you see one minute. You can imagine the kind of work that goes into it ... Planet Earth III will hopefully be in 10 years. This year has been particularly good for us because it's the 60th anniversary of Natural History and David Attenborough's 90th birthday. All the stars alined."

Whilst the show has yet to be officially commissioned, the team are already working to develop ideas.

They added to the Express.co.uk: "Planet Earth III is in our heads. We haven't started filming. It's not commissioned, but we're planning what might be a Planet Earth III. Who knows, we hope David will be with us. You never know. If he's here, he'll be doing it. That's for sure. He is the voice of Natural History. He's the voice of Planet Earth II, and if he's still willing to do it, then he'll do Planet Earth III.

"I think it's fair to say without him it definitely wouldn't be the same, no. All of us owe so much to Sir David for making the series what it is. There's no way else to tell the stories than he does. The bosses will kill me for saying Planet Earth III is happening by the way! Maybe it's good because then it will be commissioned."