The daughters of aged care residents who died following a COVID-19 outbreak at a Melbourne facility have cried in relief at the news justice is "one step closer".

A magistrate on Thursday ruled there was sufficient evidence for the case against Heritage Care to go to trial.

Heritage Care is the parent company of Epping Gardens, where a 2020 outbreak of the virus led to 89 residents and 65 staff contracting COVID.

Thirty-four residents ultimately died from COVID or related complications.

Ann-Marie Jeal's mother Olga Boyle was a resident of the home, and aged 88 when she died of the virus.

"We have eaten, breathed, slept this, ever since the night mum died," Ms Jeal told AAP.

"We want justice, we need justice, and it looks like we're on our way to getting justice with this - we're one closer step."

Connie Tropea, who lost her father Sam Tropea before the outbreak, said she lodged several complaints about the aged care home in the lead-up to the provider coming before court.

Heritage Care has pleaded not guilty to charges under health and safety legislation.

"I made a promise to my dad before he died that I would make them be accountable for their actions, so hopefully we can do this," Ms Tropea told AAP.

Magistrate Peter Reardon on Thursday ruled the case should go to trial, with it next due before the County Court of Victoria in June.

Earlier, he demanded to know why WorkSafe neglected to get a statement from Epping Gardens' director of nursing as part of its investigation into what led up to the fatal COVID outbreak.

WorkSafe informant and investigator of more than two decades Shane Grigg said his team of 10 investigators received statements from the facility's general manager Alistair Cooray and other staff as part of their probe.

However, he conceded he did not seek statements from the aged care home's director of nursing, nor its clinical services manager, quality assurance co-ordinator or infection control manager.

Mr Reardon asked him repeatedly why he did not get a statement from the director of nursing, saying "virtually every witness" referred to her as being in charge.

Mr Grigg told the court WorkSafe believed it had sufficient material from other staff to demand the facility produce documents about its processes, before later saying he didn't know why his team didn't get a statement from the director of nursing.

The magistrate reminded him 34 people had died.

"Don't give me answers like, 'I don't know why' - you do," Mr Reardon said.

Mr Grigg conceded staff had relentlessly criticised the director of nursing following the COVID outbreak and some blamed her for it.

The committal hearing was told the director of nursing distributed guidelines and instructions about COVID practices to staff.

WorkSafe alleges Heritage Care failed to provide and maintain a working environment that was safe and without risks to health between March 13, 2020 and July 20, 2020.

The watchdog alleges the company did so by failing to provide the necessary training to staff and failed to ensure residents were not exposed to health and safety risks.