Former Greens leader Bob Brown has won his High Court bid to overturn Tasmania's anti-protest laws.
The landmark case stemmed from Dr Brown's arrest while filming a video about an anti-logging protest at Lapoinya State Forest in the state's northwest in January 2016.
In a majority ruling handed down on Wednesday morning, the High Court found provisions of Tasmania's Protesters Act were unconstitutional.
"(They are) invalid because they impermissibly burden the implied freedom of political communication contrary to the Commonwealth Constitution," the judgement reads.
Dr Brown, whose police charges over the protest were dropped, said he was "delighted" by the ruling.
'Today is a great day for the forests, wildlife and all of nature in Tasmania and around Australia," he said in a statement.
"And a great day for the fundamental right of Australians to peaceful protest.
''This judgement puts a brake on corporations wanting communities sidelined."
Dr Brown argued the laws, which can fine protesters up to $10,000 and jail them for four years, were draconian and undemocratic.
The Tasmanian government introduced the laws in 2014 to protect businesses from political protests seeking to prevent, hinder or obstruct operations on business grounds or in access areas.
They contended people should not be allowed to trespass or commit nuisance against lawful land occupiers.
In parliament, Tasmania Premier Will Hodgman said his government would "appropriately consider" the High Court decision before taking any further action.
The state government has been ordered to pay Dr Brown's legal costs.
