LEIGH SALES, PRESENTER: Planet Ark is one of Australia's highest profile environmental groups, backed by celebrities like Pierce Brosnan and Kylie Minogue, and famous for its campaigns on recycling and tree-planting. But the charity, cofounded by tennis great Pat Cash, is under attack from its fellow green groups, accused of selling out to the forest industry. 7.30 has learned that Planet Ark has accepted hundreds of thousands of dollars in sponsorship from a timber lobby group and allowed its logo to be used on advertising for wood products. Tonight the organisation's founders speak out for the first time in this exclusive report from Adam Harvey.

PIERCE BROSNAN, ACTOR (Planet Ark ad): The name's Brosnan, Pierce Brosnan, welcome to Planet Ark. You don't have to be James Bond to save the world, just get on the Internet and go to Planet Ark.

ADAM HARVEY, REPORTER: Planet Ark was the environmental charity of choice for some big stars.

PIERCE BROSNAN (Planet Ark ad): Getting information you need to stay informed and make a difference.

KYLIE MINOGUE, MUSICIAN (Planet Ark ad): You know you want to and I would love you to. Recycle!

ADAM HARVEY: It was National Tree Day on the weekend and John Dee was getting his hands dirty for the event he created. Planet Ark made its name promoting recycling and events like National Tree Day, where schoolchildren and community groups plant one million seedlings around the country.

Back in 1991, John Dee and his friend, tennis great Pat Cash formed Planet Ark to promote positive environmental actions like tree planting and recycling. The pair were adept at reeling in some big names.

JON DEE, CO-FOUNDER, PLANET ARK: Pat and I went out to our network of celebrities and we managed to get some of the world's biggest celebrities to donate their time to the organisation, and that certainly helped us to really crash through and create a really potent force for change.

ADAM HARVEY: Planet Ark is now embroiled in controversy over its relationship with the timber industry, and it's accused of selling out.

SARAH REES, MY ENVIRONMENT: No environmental group should take money from the forestry sector.

CHRISTINE MILNE, GREENS LEADER: What Planet Ark has done has undermined the rest of the environment movement by effectively deciding to give some "greenwash" to the native forest logging industry.

PETER MADDISON, ARCHITECT (Planet Ark ad): Do you know the good news about wood? Nearly half this wood is carbon, removed from the atmosphere by a growing tree. It's far better for our environment to have the carbon stored for life in here than out there.

ADAM HARVEY: This Planet Ark ad is part of a campaign for wood that's paid for by Forest and Wood Products Australia.

PETER MADDISON (Planet Ark ad): And that's why more people are saying wood is naturally better.

NICK XENOPHON, INDEPENDENT SENATOR: There could be a perception of who pays the piper calls the tune - and when you're getting $700,000 in donation from the industry and you're part of a review of the forestry standard, then it raises some serious questions of a potential conflict of interest.

ADAM HARVEY: Planet Ark is also under fire for working with the timber industry to update the industry's certification system for wood products, which is called the Australian Forestry Standard. It's seen as weaker than the rival certification system, backed by the environmental movement and run by the Forest Stewardship Council.

CHRISTINE MILNE: The Australian Forestry Standard has no credibility at all. In fact it was only dreamt up in response to the Forest Stewardship Council Standard, and Australia couldn't meet that standard, and so the minister of the day went ahead and next thing we knew we had this dodgy standard which no one has any respect for.

JON DEE: The Australian Foresty Standard is a scheme that concerns many environmentalists. If you ask environmentalists about the AFS they will tell you that they're associated with clear felling, with environmental destruction, with the death of native wildlife. And so from that perspective an organisation like Planet Ark cannot be seen to be associated with that particular standard.

ADAM HARVEY: Jon Dee left Planet Ark five years ago to work on other charity projects, but he's remained a member - until now. Jon Dee and Pat Cash have resigned their memberships from the organisation that they founded.

JON DEE: We believe that this initiative - you know, the TV advertising campaign, the tie-up with the forest industry, and in particular the association with the Australian Forestry Standard, it is something that we do need to let people know Pat and I are not associated with that. We think it's one step too far.

ADAM HARVEY: Pat Cash has issued this statement to 7.30, saying "Planet Ark should be held accountable for its decision to work with the forest industry" and "return to the values that made it great." He says it should "withdraw from its association with the Australian Forestry Standard and Forest and Wood Products Australia".

Planet Ark declined 7.30's request for an interview but in a statement said it's not compromised by its deal with the forest industry.

PLANET ARK STATEMENT (voiceover): We have a long history of maintaining independence while working with sponsors, whether they are companies, industry associations or governments of all political persuasions.

ADAM HARVEY: Planet Ark's financial statements show it's been in the red three years running. Last year the charity put its former Blue Mountains headquarters on the market.

BIANCA BROWN, CENTURY 21 (promotional material): Today I'd like to show you 17.3 acres currently run at the moment by Planet Ark.

ADAM HARVEY: It sold for a bargain $875,000.

JON DEE: The fact they sold it was an issue for us. The fact they sold it for less than it was worth caused us concern, and we believe they shouldn't have sold it in the first place. It was an amazing facility that, to Pat and I, summed up everything that Planet Ark was all about. It was all about positive solutions.

ADAM HARVEY: Planet Ark's deal with the forest industry has made it easier to balance its books right now, but they may find the relationship causes long term damage with its traditional supporters.

CHRISTINE MILNE: I think it will be the beginning of the end for Planet Ark, unless they change direction. Next time Planet Ark comes on TV saying recycle your Christmas cards, people are going to say, "Oh, that's the Planet Ark that isn't saying anything about the destruction of logging native forests around Australia."

LEIGH SALES: Adam Harvey with that report and you can also read the full response from Planet Ark.