The remains were discovered on Saturday, March 16 on the Barongarook Creek Bridge.

The remains were determined to be Indigenous ancestral remains and transferred to the Aboriginal Heritage Council.

Rodney Carter, chairperson of the council, said it was very important to Indigenous people that their ancestors were returned to country so that they can rest peacefully.

"The council is humbled to have the responsibility to ensure this happens," he said.

Council member Jim Berg reiterated how important this was.

"The desecration of our ancestors' remains impacts on us, it harms us," Mr Berg said.

"We all have a part to play so that true reconciliation can be achieved and our ancestors returned back to their country for reburial, where they find peace with our spiritual mother the land, before drifting off into the dreamtime."

TUESDAY:

Human remains uncovered during works on a Colac bridge on Saturday have been identified as Indigenous.

Colac Crime Investigation Unit detectives were investigating following the discovery of human remains at the Murray Street bridge.

Detective Senior Constable Stuart Sims, of the Colac police crime investigation unit, said civil engineering workers digging trenches uncovered what was believed to be human remains about 9am.

He said a crime scene was establish soon after 9.30am and evidence was sent to an anthropologist at the Victorian Institute of Forensic Medicine.

"It was established that the remains were Aboriginal. They were collected and handed over to Aboriginal Affairs Victoria," he said.

"The age of the remains, which included a skull and other bones, could not be determined but they are very old."

The bridge over Colac's Barongarook Creek is being replaced as part of the $365 million Princes Highway upgrade from Winchelsea to Colac.

A temporary bridge is being constructed to the side of the existing bridge so the Princes Highway remains open while the old bridge is removed and a new bridge is constructed in its place.