However, the Australian Workers Union has criticised the fact that it will be an internal inquiry within the department.

The special report revealed startling claims by former Victorian Lands Department workers of appalling safety standards when working with dangerous chemicals – including Agent Orange – in the Ballarat and wider Goldfields region.

The workers also claimed complaints by spray hands regarding the chemicals were ignored by authorities and unions.

Environment and Climate Change Minister Ryan Smith said on Tuesday afternoon a full and comprehensive inquiry would be led by the Department of Environment and Primary Industries.

"These reports are concerning. A full and comprehensive examination of the issues raised will be led by DEPI," Mr Smith said.

"In the development of this advice, DEPI will consult fully and obtain all relevant information from the Victorian WorkCover Authority."

PART ONE: Former state government weed eradicators make startling claims of appalling safety standards when working with dangerous chemicals in the Ballarat and wider goldfields region.

PART TWO: Complaints by spray hands regarding chemical use were ignored by authorities and unions.

The AWU has called for the investigation to be independent.

"The problems that initially occurred in the predecessor to DEPI, the Victorian Lands Department, shouldn't be internally investigated by DEPI. These issues need a public airing," AWU Victorian secretary Ben Davis said.

"It needs a full state government inquiry, they managed to do it at Fiskville, they need to do it at this one."

"Simply talking to WorkCover is not enough, these issues and health concerns need a public airing," Mr Davis said.

"These workers have waited decades to tell their story and their story now needs to be heard. They need to talk to former employees."

The minister said the inquiry would begin immediately.

He allayed concerns for current DEPI employees.

"These reports relate to activities from several decades ago," Mr Smith said.

"Current DEPI and Parks Victoria staff and the community should be reassured that current practices and procedures used to control pest plants and animals are in line with best occupational health and safety practice."

The state Opposition said on Monday it would hold an inquiry into the matter if elected in November. 

Labor spokeswoman for environment and climate change, Lisa Neville, said the claims should be investigated.

“The Courier’s important article on the former Lands Department has shone a light on the plight of many former workers,” she said.

“Victorian Labor supports an inquiry to investigate these matters further.”