First Nations Victorians are being restrained and secluded at a higher rate than the general population, a shocking new report by the state's peak mental health advocacy body has revealed.

The Victorian Mental Illness Awareness Council third Seclusion Report found more than five per cent of people admitted to Victorian mental health facilities subjected to seclusion were Indigenous, despite First Nations people making up just 3.5 per cent of total people admitted.

The rate of restraint among Indigenous patients was also higher at 4.6 per cent.

The findings come one year after the Royal Commission into Victoria's Mental Health System found poor mental health and substance use disorders accounted for as much as 14 per cent of the health gap between Aboriginal and non-Aboriginal people.

VMIAC executive officer Craig Wallace said the new data made it clear why First Nations people might be apprehensive to seek help.

"It's these mental health services and the acute units where people are supposed to go to feel safe," he said.

"And then they're being harmed by these practices, and traumatised by these practices.

"That makes people really concerned about seeking help in the future, knowing that these things have happened to them or could happen to them."

Djab Wurrung and Gunditjmara woman and Victorian Aboriginal Community Controlled Health Organisation social and emotional wellbeing executive director Sheree Lowe said the figures revealed in the report the tip of the iceberg.

"(The figures) indicate that people might have been secluded twice in their stay," she said.

"And this is the data specifically for patients in adult acute, so in our mental health services.

"We don't capture what happens in our emergency setting...and there's a space there for young people as well."

Whilst the report details the percentage of Victorian First Nations people being restrained and secluded, there is no data as to what type of seclusion or how patients were being restrained and secluded.

Mr Wallace said the lack of data hindered the ability to properly understand the First Nations experience in mental health care.

"We don't even know what these seclusion rooms look like across the state," he said.

"And we certainly don't have enough data on whether a seclusion room is culturally safe for First Nations people, if indeed you could ever make a seclusion safe for anyone.

"The key to understanding people's experiences in the system is for us to have more data and for that data to be made easily available.

"And for us to be able to communicate that data more clearly to people who use our mental health services or might need to use our service."

The final Royal Commission report recommended funding for two healing centres to complement social and emotional wellbeing services delivered by Aboriginal community-controlled health organisations.

Funding the delivery of culturally appropriate care was also recommended.

Mr Wallace said lack of cultural safety was one of the biggest barriers to delivering appropriate care.

"To come to a hospital in your greatest time of need and be judged and secluded, so you're judged and punished is really difficult for people," he said.

"It's traumatising and it affects their willingness to want to engage with services again in the future.

"For First Nations people, it's particularly an example of something that's not culturally safe."

The Royal Commission recommended phasing out seclusion and restraint over 10 years.

The Victorian Mental Health Minister's office did not respond by time of publication.