The number of protesters at the Djab Wurrung Embassy has reached an "all time high". (Djab Wurrung Embassy)

The number of protesters at the Djab Wurrung Embassy has reached an "all time high". (Djab Wurrung Embassy) Source: Djab Wurrung Embassy

Djab Wurrung Traditional Owners say they are heartbroken following a suspected arson attack on a significant tree close to the camp where First Nations protestors and their supporters have gathered to oppose a controversial development for Victoria's Western Highway.

A tree with smoke billowing out of it was discovered just after daybreak on Monday nearby the site of a mass protest demonstration to save sacred Djab Wurrung trees located in Victoria's western districts.

Traditional Owners who have been camped out in an attempt to stop a controversial upgrade to the state's Western Highway between Ararat and Buangor said they were left feeling "gutted" by the act of vandalism.

Traditional Owner and Djab Wurrung Embassy founder Zellanach Djab Mara says he has provided local detectives with information, including troubling posts on social media that included threats to harm the trees.

"This is an Ancestor tree. It is very sacred to us," Mr Djab Mara told NITV News.

"I was gutted. It broke my heart."

Victoria Police confirmed they are investigating the matter, and urge anyone with information or dash cam footage to contact Crime Stoppers.

"All efforts are being done to save the tree with an arborist being called to assess its viability," a statement to NITV reads.

An ancestor tree, considered culturally significant to the Djab Wurrung, began to burn overnight.

Source: Supplied

The tree was still smoking at midday on Monday, in what Mr Djab Mara is calling an arson attack on his country.

The Western Highway development along a 12.5km stretch of land could potentially see nearly 1000 trees bulldozed.

The suspected attack comes in the wake of a mass gathering at the Djab Wurrung Embassy in the past week, as supporters of the land and trees brace for an imminent eviction so that construction of the bypass can begin.

An application from Djab Wurrung lawyer Michael Kennedy to protract an eviction notice was denied by the project's developer Major Road Projects Victoria (MRPV), after the Embassy's bid to receive protection from federal Environment Minister Susan Ley was knocked back.

Over the weekend ,The Age newspaper reported that key evidence was overlooked by Ms Ley in her assessment of the Embassy's application for protection.

Traditional Owners and their allies say they are prepared to put their bodies on the line to protect the land, while the embassy's lawyers continue to work to find legal means to protect the area.