Seventeen days later, she was dead from a brain injury received while in custody.

As officers from Castlemaine police station celebrated their Christmas party on December 5, 2017, the 55-year-old Yorta Yorta woman fell and hit her head five times inside a cell.

Senior Constable Stephen Thomas earlier helped escort Ms Day off the V/Line carriage at Castlemaine, after rail staff called to say an unruly, intoxicated Aboriginal woman was travelling without a ticket.

"Other people on the train had a look of disgust and it was obvious to me she made other people on the train feel uncomfortable," Sen Const Thomas on Tuesday told a Melbourne inquest into Ms Day's death in custody.

He said she smelled strongly of alcohol and her words were "almost unintelligible".

"I said to her that she had to come with us and I told her that we would try to look after her and get someone to come and pick her up."

But police couldn't find anyone else to take care of Ms Day and took her back to the station.

As she got into the back of the police van, she told the officers "here we go again, it's like this is it," Sen Const Thomas said.

"I said to her it wasn't like that and that we were trying to look after her."

Police didn't go inside her cell until she was due to be released that night. She died in hospital from a brain haemorrhage three days before Christmas.

Coroner Caitlin English has rejected a push by media outlets and the Day family to immediately release footage of the woman's time in police custody.

"It would not be fair for the witnesses to release the CCTV as a whole prior to it being played in court with the benefit of the witnesses' evidence as context," the coroner said.

She is examining whether racism contributed to Ms Day's death.

Train conductor Shaun Irvine repeatedly told the inquest he didn't recall if he realised the woman he found sleeping on seats was indigenous.

He also denied telling fellow staff or police she was Aboriginal but eventually admitted he may have said as much after being contradicted by other inquest witnesses.

The Day family's lawyer, Peter Morrissey SC suggested the conductor would not have called police if the passenger had been a white person.

"I believe I would have (done the same thing)," Mr Irvine replied.

He told the inquest he made sure police were called on Ms Day because he was concerned for her safety.

She was not bothering other passengers but was deemed unruly as she appeared delirious and couldn't provide related answers to his questions, Mr Irvine said.

He added he was worried she could fall and even be hit by a train is she disembarked by herself.

More police officers are expected to give evidence at the inquest on Wednesday.

Australian Associated Press