A coronial inquest into the death of 21-year-old Ben Catanzariti has been heard in the ACT Coroner's Court over several days last year and on Monday, but wrapped up on Tuesday following brief oral submissions from the parties. More detailed written submissions are with the court, and there was no date set down for the coroner's findings.

Barrister Bernard Collaery, who represents Ben Catanzariti's family in the inquest, asked Coroner Karen Fryar to refer the case to prosecutors for criminal charges against Schwing Australia, which had recently serviced the Schwing concrete pump owned by Belconnen Concrete, and engineer Phillip James O'Rourke.

Mr Catanzariti suffered fatal head injuries when a concrete pouring boom came crashing down on him on the Kingston Foreshore construction site where he worked on July 21, 2012.

He had been working for Belconnen Concrete for just two weeks before the incident, which also left two others injured.

Investigations found that the boom's sudden collapse was due to the fracture of high-strength bolts, but the cause of the bolts' failure has been contested since.

Three expert reports provided three different explanations for the failures. In January 2017, a fourth expert report was produced to the inquest.

The differing opinions caused the collapse of a criminal prosecution of Schwing and Engineer Phillip James O'Rourke in the ACT Industrial Court in 2012.

Prosecutors had alleged both defendants failed to comply with their health and safety duties. Schwing and the engineer had pleaded not guilty to the charges, and the allegations were set to be defended.

But after receiving and reviewing a second expert report commissioned by Schwing, and then a third through Worksafe ACT on behalf of prosecutors, the Director of Public Prosecutions John White SC released a statement in 2016 that said the office had concluded there were no reasonable prospects of conviction.

It discontinued the criminal charges.