The owner of a Bass Strait ferry service is being sued for negligence over the death of 16 polo ponies on a trip from Tasmania to Victoria earlier this year.

Polo identity Andrew Williams has lodged a writ in the Victorian Supreme Court accusing Spirit of Tasmania operator TT-Line and logistics company QUBE Holdings Limited of failing to provide a safe environment for the horses.

The horses were being taken by Mr Williams to the mainland in January in two floats after a polo tournament in Tasmania’s northeast.

They died sometime during the Bass Strait crossing after boarding the ferry in Devonport, the writ says.

It is alleged TT-Line and QUBE Holdings Limited failed to provide adequate ventilation for the horses and adequate monitoring of their condition during the journey.

Mr Williams, along with his partner Rebecca Williams, Twynam Agricultural Group and Willo Polo, want $739,000 in damages for the value of the horses and lost wages.

One of the specially bred horses, Felitas, was worth $120,000.

Mr Williams and his driver parked the horse floats on the ferry and were told by staff to not return until directed the following day, the writ says.

A Tasmanian government investigation into the deaths is ongoing, Racing Minister Sarah Courtney told parliament on Wednesday.

Tasmania’s Department of Primary Industries, Parks Water and Environment (DPIPWE) has come under fire for not releasing autopsy results.

“This is a complex matter across three jurisdictions,” Ms Courtney said.

“Information will only be released when it its appropriate to do so, in line with confidentiality and legal requirements.”

Ms Courtney said the horse deaths was an “isolated” matter and there was no ongoing risks to transporting horses and livestock across Bass Strait.

DPIPWE said in March the cause of the deaths was not clear.

TT-Line and QUBE Holdings have been contacted for comment.

-AAP