Victoria's truth telling inquiry, the Yoorrook Justice Commission, will run until June 2025 after being granted a 12-month extension by the Victorian government on Tuesday.

The state has agreed to the extension in response to Yoorrook's recommendation in its interim report last year.

The extension provides additional time for Yoorrook to gather evidence on the systemic injustice faced by First Peoples in Victoria and for making recommendations for transformational change, including to support Victoria's Treaty making process.

The Victorian government also granted a two-month extension for Yoorrook to deliver its critical issues report on the Commission's current inquiry into systemic injustice within the child protection and criminal justice systems. This report is now due at the end of August 2023.

Yoorrook, Victoria's formal truth telling inquiry, is the first of its kind in Australia.

Chair of the Commission, Professor Eleanor Bourke said the extension is critical for Yoorrook to deliver on its historic mandate to make "bold and transformative recommendations" that address the systemic injustices faced by First Peoples in Victoria.

"The expectation is that these recommendations will be implemented in full by the Victorian government," she said.

"The extension is not everything Yoorrook asked for, but it is significant and provides important certainty over the future of the Commission.

"An essential part of Yoorrook's work is to build a shared understanding of the true history of our state, as well as the ongoing, and often devastating, impact of colonisation on First Peoples."

Professor Bourke said the final six months of Yoorrook's operation will aim to ensure that the stories and truths shared by First Peoples are not only recorded, but understood by all Victorians.

"This legacy is for generations to come," she said.

"Every witness, and every story is important. I take this opportunity to thank all those who have contributed to Yoorrook's rich evidence base so far.

"These are unprecedented times in Victoria with strong progress relating to Truth and Treaty. In many respects Victoria is leading the nation. Yoorrook is the first formal truth telling inquiry in Australia. The Yoorrook Justice Commission looks forward to making a significant contribution to the history of Victoria."