Warning: Graphic content

Victoria Police has urged a coroner to dismiss the "opinions" of Yorta Yorta woman Tanya Day's family, who want individual officers to be criminally investigated over her death in custody.

Tanya Day died after falling in a police cell.

But Ms Day's family argue the force is trying to skirt its responsibility and remain optimistic coroner Caitlin English won't let them do so.

The 55-year-old grandmother fell and suffered a head injury while in a regional Victorian police cell after being arrested for drunkenness on a train on December 5, 2017. She died two weeks later.