Ken Grant, father of former police minister Troy Grant, claims sleepwalking over fatal hit-and-run

Ken Grant, a 71-year-old retired police officer on Monday pleaded not guilty to dangerous driving occasioning death, failing to stop and assist after impact causing death and police pursuit and faced the first day of a judge-alone trial.

Ken Grant is accused of running down scientist Tony Greenfield on Flat Road, Bolwarra between 11.20pm and 11.30pm on November 30, 2019.

The pair had been at the same Christmas party and Mr Greenfield was walking the short distance to his accommodation when he was struck from behind and killed. Ken Grant, who witnesses at the party described as being "hammered" and "extremely intoxicated", did not stop after the crash and, a short time later, led police on a pursuit along Belmore Road at Lorn despite driving with two flat tyres.

"My son is Troy Grant, the police minister," Ken Grant immediately told police after he finally pulled his car over. "I am pissed."

A breath test revealed Ken Grant had a blood alcohol reading of 0.108 and in interviews with police he claimed to have no knowledge of the fatal hit-and-run on Flat Road.

During his opening address, Crown prosecutor Lee Carr, SC, told Judge John Hatzistergos that much of the events of the night, including the crash and subsequent low-speed pursuit, would not be in dispute during the trial, with the focus on whether or not Ken Grant's driving was "voluntary".

The estimated five-day trial will hear from a number of medical experts in neurology, gerontology, neuropsychology and a sleep expert, the court heard.

Defence barrister Philip Boulten, SC, said Ken Grant had a history of sleepwalking that has involved "very complex motor skills", including "irrigating a field as a farmer".

He said one expert was of the view Ken Grant's driving "could have been undertaken while the accused was not acting voluntarily".