The Victorian coroner has released graphic security footage showing the chain of events which led to an Aboriginal woman sustaining the traumatic brain injuries which would ultimately kill her.

Family members gasped and wept as the footage showing Tanya Day stumbling before slamming her head into a concrete wall was played at the inquest into her death earlier this week.

The acting state coroner, Caitlin English, today approved the release of the footage and said she did so with the support of Ms Day's family.

Tanya Day died in hospital 17 days after hitting her head in a police cell. ( Supplied )

"Unusually, Ms Day's family advocates strongly for the release of the CCTV footage," she said.

"The family's position is that it is consistent with Ms Day's memory and dignity that CCTV is released.

"It is in the public interest to release the CCTV footage that has been played in court."

Ms Day, 55, hit her head five times while she was in custody at the Castlemaine Police Station, after being arrested for being drunk in public in December 2017.

She died in hospital 17 days after she was first detained.

Outside court, Ms Day's daughter Belinda Stevens said it had been "unbearably painful" for the family to watch the video, which showed her mother's final moments of consciousness.

"When you watch this harrowing footage, know that this is a strong, proud and loving Yorta Yorta mother, grandmother, aunty and activist," she said.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 1 minute 27 seconds 1 m 27 s Tanya Day's daughter Belinda Stevens said she wants the world to see the footage.

"Our mum died because Victoria Police targeted her for being drunk and then failed to properly care for her after they locked her up in a police cell."

"Our mum deserved to be treated with dignity and care but was instead ignored and left to die on the floor of a police cell.

"We want the world to see this footage because Aboriginal deaths in custody must end."

Paramedic 'felt sorry' for Ms Day

Less than an hour into her incarceration, security footage shows Ms Day standing up and stumbling, before falling forward and slamming her head into the concrete wall above her bed.

The force of the blow was so strong that medical experts are expected to tell the Coroner in the coming days that it caused a significant brain haemorrhage.

The most significant blow happened just one minute after two police officers checked on her.

On Friday the inquest heard evidence from paramedic Lisa Harrup, who first attended to Ms Day on the night an ambulance was called.

She said she would have altered her course of action had she known the 55-year-old had fallen several times.

Security footage from the night shows Ms Harrup performing a number of mobility and balance tests on Ms Day in the cell.

She wept and looked to Ms Day's family as she gave evidence, and apologised for the distress those tests caused.

"I was neither intentionally rough with Ms Day nor disrespectful," she said.

"I actually felt sorry for Ms Day because she'd been kept in a dirty, foul smelling concrete cell for four hours.

"I would've handled my own mother or sister the same way I handled Ms Day."

But Ms Harrup's evidence appeared to infuriate Ms Day's daughter, Apryl Watson, who stormed out of court and shook her head during the evidence.

Tanya Day pictured with her daughter Apryl. ( Supplied )

Sergeant 'didn't know' about fall

The Victoria Police manual requires prisoners like Ms Day to be physically checked and roused every 30 minutes, and had this been followed, officers would have been present just minutes after the fatal fall.

But instead, officers instituted their own checking regime.

They did not enter Ms Day's cell for hours.

Ms Day suffered another small fall before she was checked through the cell door about 45 minutes later, by the watch house keeper, Leading Senior Constable Danny Wolters.

Footage shows the police officer looking through the door for just less than four seconds before leaving.

When questioned about the length and quality of the physical check at the hearing yesterday, Leading Senior Constable Wolters said he did not want to compromise Ms Day's dignity.

He said Ms Day was in an "undignified position for a lady to be in".

"I found it a little bit confronting," Leading Senior Constable Wolters said.

"I didn't want to get caught leering at her."

But barrister Peter Morrissey SC, who is appearing on behalf of Ms Day's children, challenged that.

"This was a completely inadequate physical welfare check," he said.

"This whole dignity argument is a flat out lie ... to cover your behaviour.

"She lay there for three hours after that fall without anyone coming in."

Tanya Day was arrested after being found asleep on a Melbourne-bound V/Line train. ( Supplied )

Earlier, Mr Morrissey questioned Sergeant Edwina Neale, who was the officer in charge of Castlemaine Police Station that evening.

Sergeant Neale said she did not know that Leading Senior Constable Wolters was not going into the cell to check on Ms Day.

"I'm putting to you, she was at risk of falling over and cracking her head," Mr Morrissey said.

Sergeant Neale responded: "She was no more a risk than any other intoxicated drunk."

Mr Morrissey put to her that "it was negligent of you ... not to go in and check her, if you knew she had that fall".

Sergeant Neale said she did not know Ms Day had fallen.

The inquest continues.