Work on a Melbourne highway upgrade has been shut down after contractors disturbed asbestos, a union says.
The CFMEU claims earthworks for the Chandler Highway upgrade at Alphington were halted on Thursday after lead contractor Seymour Whyte disturbed asbestos.
This also shut down demolition work at a paper mill across the road and the construction of a nearby residential tower.
The union's occupational health and safety manager Gerry Ayers accused Seymour Whyte of disregarding worker and public safety.
"The contractor would have known there was asbestos in the soil and has blatantly disregarded the knowledge," Dr Ayers told reporters.
"There was no type of any dust suppression whatsoever .... there's potentially a huge amount of exposure."
At least 100 workers have been potentially exposed to the asbestos during work over the past few months, CFMEU organiser James Simpson added.
"They have moved a lot of asbestos around the site, put a lot of people in potentially harms way," he said.
The government is spending $110m to widen the Chandler Highway to six lanes and building a new bridge but it's not clear when works will resume.
Seymour Whyte and the office of Roads Minister Luke Donnellan directed media enquiries to VicRoads, who have been contacted for comment.
Premier Daniel Andrews said the government will investigate the issue.
"I'm not aware of what the contract arrangements have been, but the most important thing here is that work has stopped in a particular part of this project because there were concerns about the safety on that site."