The answer his family has desperately awaited for two-and-a-half years has been delayed for at least another three months.

The inquest into the workplace death of the Yass construction worker was on Monday suspended so Canberra prosecutors can consider laying criminal charges.

Chief coroner Lorraine Walker found there were grounds to believe an indictable offence had been committed when Mr Vickery was killed at a northside building site in December 2011.

Ms Walker ordered a halt to the inquest until August so she could invite the Director of Public Prosecutions to decide whether to pursue a criminal case.

The law requires the coroner to write to the DPP once reasonable suspicion has been established.

Mr Vickery, 45, a veteran of the building industry, was fatally struck by a heavy grader on a West Macgregor building site on December 12, 2011.

He was working for Canberra Contractors on a Village Building Company project.

On Monday, the Coroners Court heard Mr Vickery and a co-worker had been levelling a road on the project.

Mr Vickery had been checking levels on foot, while the co-worker drove the grader.

The court heard Mr Vickery used an unconventional method to check levels, requiring him to get on his hands and knees.

He would usually complete the check while in front of the vehicle.

The pair had communicated via eye contact and hand gestures.

The grader had a warning alarm when placed in reverse and a rear view mirror, but no side mirrors.

About 2pm, Mr Vickery had crouched behind the machine to conduct a check when the grader reversed into him.

Counsel assisting the inquiry, Murray Thomas, told the court there was reasonable belief there had been negligence on the behalf of Canberra Contractors and five employees, including the grader driver.

Ken Archer, acting for driver and company, also urged Ms Walker to write to the DPP so the long-running matter could move forward.

Ms Walker said she had a reasonable suspicion an indictable offence had been committed.

The coronial inquiry can only resume after the DPP indicates it will not prosecute, or three months elapses without charges being laid.

Ms Walker adjourned the inquest for mention on August 26.

Outside court, Mr Vickery’s wife, Fiona, expressed her frustration at yet another delay.

“I want it over with. It’s very long and drawn out with no answers,” Mrs Vickery said.

After years of attending hearings, the family are still seeking basic answers.

“Why did Wayne die? If everything was the way it was supposed to be, how was it then, why did he die? I need to know that answer," she said.

“I don’t want any prosecution, but I also don’t want this to happen to anyone else’s family.

“I hope [changes] can be put in place, sooner rather than later, and there’s consequences for them not being put in place.”