An inquest into the deaths of six children in a primary school jumping castle tragedy in Tasmania is unable to progress because the state’s workplace safety regulator won’t hand over “crucial” material.

Zane Mellor, Peter Dodt, Jalailah Janyne-Marie Jones, Addison Stewart, Jye Sheehan and Chace Harrison were killed following the incident at Hillcrest Primary School on December 16, 2021.

They were enjoying celebrations on the final day of term when a wind gust lifted the castle and several inflatable Zorb balls into the air.

An administrative inquest hearing on Tuesday was told WorkSafe Tasmania had refused to pass on documents, including expert reports, because it could prejudice the regulator’s ongoing investigations and potential prosecutions.

Top, from left: Jalailah Jayne-Maree Jones, Chace Harrison and Addison Stewart. Bottom, from left: Zane Mellor, Peter Dodt and Jye Sheehan.

Lawyer representing WorkSafe Tasmania, Sam Thompson said the regulator had referred information to the director of public prosecutions for a determination on whether charges would be laid.

Coroner Olivia McTaggart adjourned the inquest indefinitely, saying it was unable to progress without the documents, which include engineer and geotechnical expert reports.

“Unfortunately WorkSafe have chosen to take action to, at this stage, prevent disclosure of crucial material that I need to progress the inquest,” she said.

“My obligation is to obtain all relevant information.”

In a statement, WorkSafe Tasmania said it had commenced proceedings in the Supreme Court of Tasmania to prevent information it considered privileged from being released.

WorkSafe Tasmania executive director Robyn Pearce said the investigation was “unprecedented in its nature and scope” and the file contained more than 40,000 documents.

“While a decision is yet to be made on whether there will be any prosecutions as a result of what happened at Hillcrest, it has not been common in Tasmania for an inquest to precede a prosecution,” she said.

“We have the utmost respect for the coronial process and by commencing this proceeding we hope to clarify our legal duties so that justice is achieved.”

A hearing in the Supreme Court of Tasmania about whether the material can be provided to the coroner will likely occur in April.

Mr Thompson said the inquest delay was “regrettable” but the integrity of WorkSafe Tasmania investigations and possible prosecutions had to be protected.

He said an initial investigation had been completed and a second supplementary investigation was in its early stages.

The court was told any decision to prosecute must be made by December 16.

Ms McTaggart said she was “hopeful” the issue could be sorted out within two or three months.

Three children also suffered serious injuries in the incident, which was described at an earlier pre-inquest hearing as a “mini-tornado” wind event.

A public ceremony was held in Devonport late last year to mark the one-year anniversary.

– AAP