Suggestions a Victorian coroner could be seen as having formed an alliance with families of residents who died in a Melbourne aged care home have been labelled "ludicrous".
Two of the home's bosses have gone to Victoria's Supreme Court to stop State Coroner John Cain forcing them to give evidence at an inquest into the deaths of 50 residents in 2020.
St Basil's Home for the Aged chairman Kon Kontis and director of nursing Vicky Kos have both refused to give evidence on grounds of self-incrimination.
The pair was running the home when 45 residents died from COVID-19. Another five residents died during an outbreak that began on July 9.
Their barrister Ian Hill QC told the court that WorkSafe was using the inquest as a "dress rehearsal" for criminal proceedings against the pair.
His arguments against Judge Cain's order for them to give evidence - with the protection of a ruling that nothing they say could be used against them in a criminal case - included an apprehension of bias.
Mr Hill took issue with a decision by Judge Cain to sit at the bar table and allow families of deceased residents to call him John while hearing from them about the impact of the deaths.
Several family members were open about their desire for Mr Kontis and Ms Kos to be made to give evidence and told the coroner so before he handed down his decision.
But to suggest the experienced judge could be perceived as having formed an alliance with family members was "ludicrous", according to government barrister Edwina Brown on Friday.
Colin Mandy SC, representing the Coroners Court in the proceeding, said the prospect of criminal charges in connection with a death being investigated by coroner was not unusual.
"The prospect of criminal charges is often an issue, whether it's peripheral or speculative, or real or uncertain," he said.
Mr Hill said there had already been four other investigations that touched on the same topics as the inquest.
He said it wasn't just open to Judge Cain to force the pair to give evidence before closing the inquest.
Alternatives included adjourning the inquest until after any criminal proceedings are concluded, or delivering interim findings pending further proceedings.
Justice Stephen O'Meara will hand down his decision at a later date.