UPDATE: new information has come to light since publication which reveals the artwork is not by Revel Cooper as claimed by the City of Greater Geelong, rather by Ben Fennessy.

A mural at Victoria's Old Geelong Gaol has been identified as the work of well-known First Nations artist Revel cooper.

Cooper, a Stolen Generations Noongar man, was imprisoned at the jail in the 1960s and 70s and had previously been taken to the Carrolup/Marribank settlement in WA's south in the 1940s.

It was at Carrolup where Cooper developed his artistic skills, becoming part of the incredible story on the child painters of the settlement.

Despite spending much of his life in prison, Cooper still sold paintings and was a prominent influence on First Nations artist Lin Onus.

First Nations Kangaroo Crocodile skeleton art at the Old Geelong Gaol

Old Geelong Gaol general manager Deb Robinson said the Gaol closed in 1991 and the remaining prisoners were transferred to the newly constructed Barwon Prison.

"It's believed that Revel worked on a number of paintings while he was in prison in Geelong," she said.

Many of his works were exhibited in galleries in the 1960s while others, like this mural, were believed to have been lost."

Cooper's work is found in collections including the National Gallery of Australia, the Art Gallery of Western Australia, Holmes à Court Gallery, Fremantle Prison, and the Berndt Museum of Anthropology.

The 12x3m mural, located in the gaol's chapel features two people looking at a sunset.

Other inmates have added images of a reptilian kangaroo and crocodile, an early design of the Aboriginal flag, and Bungdil (a wedge tailed eagle) with a rabbit in its claws.

The work was uncovered through a $60,000 local government grant designed to conserve cultural heritage.

Wadawurrung Traditional Owners Corporation chief executive Paul Davis said the project highlighted the strength and resilience of Indigenous people.

"This is about so much more than an artwork," he said.

"It's about building respect for First Nations culture and recognising the layers of impact and trauma suffered as a result of so many factors including the overwhelmingly disproportionate levels of incarceration of First Nations People."

Cr Aitken, Julie Saylor Briggs and Cr Mason with the Revel Cooper work

City of Greater Geelong councillor Anthony Aitken said the grant had helped uncover a lost piece of Djilang's (Geelong's) history.

"Heritage grants in Greater Geelong have always focused on European settlers," he said.

"We want to start shifting the balance and draw attention to one of the oldest continuous cultures on the planet.

Cr Aitken said Cooper's work was a fitting addition to Djilang's arts and culture collection.