Australian businessman Dick Smith has pledged to help Australian Greens leader Bob Brown pay a $240,000 legal bill which is threatening to force him into bankruptcy.

Senator Brown has to pay the money to Forestry Tasmania after failing in his efforts to stop logging in Tasmania's Wielangta Forest.

He has told The World Today that he has been inundated with offers of support, including a $50,000 interest free loan, a $900 stimulus payment, and a cake for a raffle.

Senator Brown says he has been told he could end up bankrupt and lose his seat in the Senate if he does not pay.

Speaking from his helicopter over Lake Eyre today, Mr Smith said it was inappropriate for the industry to threaten someone's political future.

"I'm very disturbed when I understand the legal letter which came in to Bob Brown threatened to make him a bankrupt, and of course, Forestry Tasmania would know that means he'd have to vacate his seat from Federal Parliament," Mr Smith said.

"And I don't really like that at all. I think that type of threat is quite uncalled for in Australia."

Mr Smith says he and other entrepreneurs will help Senator Brown raise the money if needed.

"I believe it's just not acceptable and Forestry Tasmania will do themselves great damage if they think they can remove Bob Brown from Parliament because he doesn't have much money," he said.

"I know if need be, I'll come in with some money and I'm sure others will too."

Forestry Tasmania says Senator Brown has known about the debt for a long time and the case has cost the organisation more than $800,000.

Ken Jeffreys from Forestry Tasmania says Senator Brown refused a compromise offer that would have reduced the court bill he owes the company.

Prime Minister Kevin Rudd says he is distressed to read that Senator Brown is under pressure to pay the legal bill.

But Mr Rudd has told Sky News he does not know the facts of the case.

"I've actually got a lot of time for Bob just as a person, a bloke I've got to know over the years," he said.

"I didn't actually know these facts until I read them in the press today so I'm quite concerned about it for him personally.

"As for what can be done about it, that's a separate matter."