A worker has died after falling six metres into a trench at a construction site north of Melbourne.

Initial reports from police suggested that the trench may have collapsed, but fire crews now say that it's believed the man simply fell into the deep ravine by mistake.

"There’s been no actual physical collapse of the trench," the Country Fire Authority's Mark Owen told 9NEWS.

“It’s believed that the gentleman may have just stepped off the edge by mistake.”

Emergency services responded to the scene on Springridge Boulevard in Wallan after the worker fell just before 3pm.

The worker, who has yet to be formally identified, died at the scene.

The man was working with a construction team to build a drainage system at the site, which is being developed into a new housing estate.

The incident has shocked his work mates, who witnessed the tragedy unfold, as well as nearby residents.

“It just was a big shock that someone has actually passed away. I feel for their family and their work mates that work with him every day,” local resident Melissa Chesmar said.