The BBC is reportedly keen to make a third series of the critically acclaimed and ratings jugernaut Planet Earth before its veteran host David Attenborough turns 100.

The finale of the second season, which took four years to make, trounched this year's X Factor final in the ratings when the two shows went head to head and it even attracted more younger viewers.

Attenborough, who is now 90, closed the new series with a heartfelt plea about protecting our planet and all of the creatures that live in it, which really hit home with viewers.

Now, producers say they want to make another series of the hit show with Attenborough, whom they describe as irreplaceable.

"It's pointless trying [to replace him]. We love working with Sir David and I think he loves working with us, and we want that to last as long as possible", said producer Mike Gunton.

"When he decides he doesn't want to do anymore, we will have to rethink how we make these programmes."

"Also, it takes an enormous amount of time to research it. You can't just go and look on Wikipedia. Often the stuff we film has not been published, it's stuff we hear about through word of mouth. So it's a huge amount of resources, but it's the only way it can be done."

Could Planet Earth III be in the works?

Gunton previously said it would be "crazy" not to attempt another series, and spoke about the time scale needed to get it done.

"Part of it is the sheer logistical necessity of getting people from A to B. If you are going to spend a month or six weeks filming in Siberia, and then you have to get to Namibia, it physically takes you a long time", he said.

"Also, it takes an enormous amount of time to research it. You can't just go and look on Wikipedia. Often the stuff we film has not been published, it's stuff we hear about through word of mouth. So it's a huge amount of resources, but it's the only way it can be done."

It would be 2026 until Planet Earth III would hit screens

The first series of Planet Earth hit screens in 2006, with the second following a decade later, meaning it could be a long wait until for Planet Earth III to be aired.