A woman claiming to be the mother of a Porsche driver allegedly involved in a crash that killed four police officers in Melbourne says his family is “ashamed”.

The woman, who did not wish to be named, read a statement to Melbourne radio 3AW on Monday, making it clear Richard Pusey, 41, had been estranged from the family for some time.

She said the family had been thrust into the spotlight, and had received threats, following the fatal crash on the Eastern Freeway on Wednesday. But they shared the same feelings of devastation as the wider community, she said.

“I want to read a statement on behalf of the Pusey family because we want to disassociate ourselves with the tragedy that occurred on Wednesday night,” she said.

“We were incredibly shocked and deeply ashamed by the [alleged] events that unfolded surrounding the accident and thereafter.

“Our family have [sic] been under public scrutiny since that time in a quest to find some explanation as to Richard’s [alleged] actions in this catastrophic event.

“This is an insight we are unable to provide.”

The alleged events referred to are before the courts.

Senior Constable Lynette Taylor, Senior Constable Kevin King, Constable Glen Humphris and Constable Josh Prestney died when a semi-trailer crashed into them while they were trying to impound Mr Pusey’s Porsche in an emergency lane on the freeway at Kew.

Senior Constable Kevin King, Leading Senior Constable Lynette Taylor, Constable Josh Prestney and Constable Glen Humphris.

Mr Pusey, of Fitzroy, was charged on Friday with nine offences including driving at a dangerous speed, reckless conduct endangering life, failing to render assistance and drug possession.

He remains in custody on remand.

Meanwhile, the truck driver accused of killing the four officers faced court on Monday.

Mohinder Singh, 47, from Cranbourne in Melbourne’s south-east is charged with four counts of culpable driving over the deaths of Leading Senior Constable Taylor, Senior Constable King and constables Humphris and Prestney.

Mr Singh didn’t speak and kept his head down during the hearing in Melbourne Magistrates Court on Monday.

His lawyer Steven Pica said Mr Singh had anxiety and depression and might have had an undiagnosed psychiatric issue throughout his life.

“Mr Singh remains distressed and saddened at the tragic consequences of his acts,” he said.

He did not apply for bail.

Meanwhile, tributes are still flowing in for the four police officers killed in the tragedy.

The family of Constable Prestney paid tribute to their son and brother in a death notice printed in major Melbourne newspapers on Monday.

“Our hearts will ache forever, and not a day will pass when you are not in our thoughts. Watch over your brother, walk beside him and every serving member,” the message reads.

“We will play for you, ride for you, run for you, cheer for you and have a beer for you. You will forever be our blue-eyed boy with the beautiful smile.”

The crash scene on the Eastern Freeway last Thursday morning. Photo: AAP

Elsewhere, Victoria Police raided two Melbourne homes in their investigation into the deadly crash.

Police searched properties in suburban Frankston and Croydon associated with the trucking company on Monday.

Assistant Commissioner Libby Murphy said it was part of the investigation led by the major collision investigation unit.

The prime mover was registered in Queensland, with plates XV85IE, and the trailer registration was 84IQWQ, she said.

Police want witnesses to hand over dashcam footage of the prime mover involved in the April 22 crash.

Assistant Commissioner Murphy said she went through the academy with Senior Constable Taylor 31 years ago and all four deaths were “heartbreaking”.

The trucking company, Connect Logistics, released a statement about the tragedy late on Monday afternoon.

“We are devastated by the loss of Senior Constable Kevin King, Senior Constable Lynette Taylor, Constable Joshua Prestney and Constable Glen Humphris last Wednesday night,” it said.

“Our prayers and deepest condolences go out to their families, the Victoria Police and everyone dealing with this horrific loss.”

It said staff were heartbroken by the deaths but would not comment further because the incident was still being investigated by police.

-with AAP