Investigations are underway after a bronze Aboriginal artwork was stolen from the Lake Macquarie suburb of Belmont at the weekend.

Thieves cut through a bronze cast of an Aboriginal stringybark canoe, the centrepiece of 'Gunyah and Canoe,' a major public artwork for Lake Macquarie City Council's Fernleigh Awabakal Shared Track project.

The artwork, installed just four months ago, was created by Julie Squires, Shellie Smith, and Daniella Chedzy to honour the Awabakal people's cultural heritage.

It was modelled on a life-sized bark canoe crafted traditionally used by Aboriginal community members led by Worimi canoe-maker Luke Russell.

The piece also included bronze casts of flathead fish, fishhooks, and twine.

Artist Julie Squires expressed disbelief and sadness at the incident.

Ms Squires told the Lake Macuarie City "absolutely heartbreaking."

"We went to extreme lengths to prevent theft," she said.

"Cutting through the bronze would have taken hours, and the sculpture weighed hundreds of kilos, requiring multiple people to move."

Ms Squires added the thieves may have mistaken the sculpture as copper, but bronze is a copper-tin alloy.

Copper is often targeted for its high scrap value.

Despite comprehensive anti-theft measures, including welding, concreting, and additional reinforcement, the thieves managed to cut through the bronze itself.

Council Deputy CEO Tony Farrell described the theft as devastating.

"Great care and effort went into creating the canoe and the accompanying bronze gunyah to ensure they were accurate representations and meaningful symbols of the area's Aboriginal heritage," Mr Farrell said.

Mr Farrell noted the sculpture had quickly become a landmark and highlighted its importance in showcasing Belmont Lagoon's historical use by the Awabakal people.

Bahtabah Local Aboriginal Land Council CEO Carol Proctor voiced her disappointment.

"This theft disrespects an important cultural representation for our mob and removes it from a site of great significance to us," Ms Proctor said.

Authorities urge members of the public with information or who may have witnessed suspicious activity to contact the council on 4921 0333 or Lake Macquarie Police/Crimestoppers on 1800 333 000.