In a neighbouring prison cell, a bird has been painted delicately onto the wall above rolls of toilet paper.

The prisoners – among them Arthur Stanley "Neddy" Smith, George Freeman and Darcy Dugan – have long since gone but what was the oldest serving jail in the country remains locked up and deserted, with an uncertain future.

The state-heritage listed Parramatta Gaol, the construction of which began in 1835, is empty as a land claim dispute between the NSW Aboriginal Land Council and state government continues.

The claim may take years to process and heritage advocates are fearful the site will go to ruin if it remains unused, and the public be deprived of the chance to see inside one of the most intact of Australia's pre-1850s jails.

The government decommissioned the minimum-security sandstone jail in October 2011. It is understood that, while ownership was being transferred between government departments, the NSW Aboriginal Land Council lodged a claim for the site on behalf of the local Deerubbin group in February 2012.

Under the Aboriginal Land Rights Act, crown land can be claimed if it is "not lawfully used or occupied" or is not needed for an "essential public purpose" or residential housing.

The claim was rejected by the government, but an appeal has been lodged in the Land and Environment Court.

A long-term plan for the jail won't be finalised until the claim is settled and, in the meanwhile, the site has been mainly used as a set for television series, including Home And Away, Rake and Underbelly. 

Parramatta MP Geoff Lee says he wants the jail to become an arts and entertainment precinct, where the cells are turned into studios and there is al fresco dining in the prison yards. Other proposals include turning the jail into a microbrewery, a backpackers' hostel or an art gallery.

"It really is a fantastic asset," Mr Lee said.

The jail will also form a key part of UrbanGrowth NSW's Parramatta North Urban Renewal project, which has the aim of creating a masterplan for the use of major heritage sites in the area.

A Land and Environment Court spokeswoman said it was not known when a judgment would be made on the claim but the matter was due for a "brief hearing" in November, nearly three years after it was lodged.

Western Sydney Heritage Action Group member June Bullivant said, even when the claim was settled, it could be years before any long-term use for the jail would be determined.

"It's just sitting there, going to waste," Ms Bullivant said. "I call it demolition by decay. It just sits there not being used. I worry for the building. I don't think anything will happen. I reckon I'll be dead first."

UrbanGrowth NSW would not comment on the land claim, but a spokesman said options for the site would be considered after the legal process.