The 55-year-old Yorta Yorta woman suffered a head injury while in custody in regional Victoria after she was arrested for being drunk on a train on December 5, 2017. She died two weeks later.

Detective Senior Constable Scott Riley, from the coronial support unit, was questioned on Wednesday about "inaccuracies" in a witness statement by Leading Senior Constable Danny Wolters, who was partly responsible for monitoring Ms Day in custody.

In a statement dated December 6, 2017, Sen Const Wolters said he checked on Ms Day in her cell.

But Det Snr Const Riley noted "the evidence is different to that".

That was in light of the CCTV footage of Ms Day at the Castlemaine police station, inside the cell, and of the corridor, where police checked on her through the door.

The footage shows Ms Day falling five times in a two-and-a-half-hour period.

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Police entered the cell four hours after she was arrested and noticed a bruise on her forehead and called an ambulance.

Paramedics weren't told about the 4.51pm fall, when Ms Day hit her head against a concrete wall. Medical experts later deemed the fall caused a brain bleed that led to her death.

Sen Const Wolters and Sergeant Edwina Neale, who were on duty that night, maintain they didn't see Ms Day fall. But Sen Const Wolters said in his statement he did see the fall, the inquest was told.

Det Sen Const Riley said he knew Sen Const Wolters didn't follow the policy to check on Ms Day and had learnt to his "surprise" the officer at times used an intercom to contact her.

Despite the conflicting information, Det Sen Sgt Riley didn't seek clarification and decided to let the Coroners Court decipher the evidence.

"I think that evidence to be more appropriate to be tested in court because we have not identified any criminal offence," Det Sen Sgt Riley said.

"There is no power to arrest in relation to that. You still gotta have to form police briefs, reasonable grounds and a criminal offence."

Det Snr Constable Riley said he was not aware of the police seeking legal advice about a possible criminal case and assumed an internal review of the incident would take place.

The Day family have previously raised concerns about the adequacy of Det Sen Const Riley's investigation.

The inquest before coroner Caitlin English continues on Thursday, with Det Sen Const Riley back on the stand.

Australian Associated Press

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