Major Roads Project Authority workers were excavating near the Barongarook Creek bridge on Colac's Murray Street around 1.30pm on Thursday when they discovered what they believed were human bones.

Project authority program director Tim Price said work was immediately halted in the surrounding area while police were notified.

An exclusion zone is now in place.

A Victoria Police spokeswoman said detectives were conferring with Coroner Court pathologists before proceeding the investigation further.

The discovery comes months after workers found Aboriginal ancestral remains while excavating near the same bridge in March.

The workers are building a new bridge to replace an 80-year-old bridge on Murray Street as part of Princes Highway upgrades between Winchelsea and Colac.

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