Steven Woodhouse died in Reservoir in Melbourne's north on November 11, 2023, after he was detained by Critical Incident Response Team officers.
Mr Woodhouse's sister Shaye is suing Victoria Police in the Supreme Court, alleging the officers breached a duty of care and committed assaults during the arrest.
A writ filed earlier in December states Mr Woodhouse suffered catastrophic injuries when he was shot at with bean bag rounds and tasered.
The officers were not named in the civil lawsuit, although their identities are known to the Woodhouse family and police.
It's also alleged Victoria Police failed to properly supervise, control or train their employees, officers and/or agents.
Ms Woodhouse is seeking aggravated and exemplary damages, claiming she has suffered injury and loss as a result of her brother's death.
A Victoria Police spokeswoman said there was an ongoing Homicide Squad investigation into the incident.
The Professional Standards Command was also overseeing the process as was standard practice for a death in custody, the statement said.
"Investigations of this nature are often complex and Victoria Police is committed to ensuring they are investigated thoroughly," the spokeswoman said.
"We acknowledge the impact incidents such as this have on all parties involved and endeavour to prioritise them accordingly, however there will be circumstances where investigations take more time for different reasons."
It comes after two officers were charged following the death of Luke Briggs during a separate incident in Melbourne's southwest in July 2024.
The 35-year-old builder allegedly became unresponsive during an arrest in Hoppers Crossing and died in hospital eight days later.
Constable Alexander Papanastassis, 29, and Sergeant James Fitzgerald, 49, were each charged with negligent manslaughter over Mr Briggs' death and faced court in September.
Mr Briggs' family also filed a civil lawsuit against Victoria Police in October, claiming the two officers breached their duty of care.
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