A driver has been charged with five counts of dangerous driving causing death after a “catastrophic” crash that killed five people just south of the Victoria-NSW border.

Victoria Police allege the crash – the state’s deadliest since 2012 – occurred only minutes after officers pulled over the speeding driver of one of the cars involved.

Initially they said the collision at the intersection of the Murray Valley Highway and Labuan Road at Strathmerton, about 210 kilometres north-north of Melbourne, on Thursday claimed three lives.

On Friday afternoon that was increased to five as police revealed more details about the horrific incident. A dog also died.

Assistant Commissioner Glenn Weir said the scene at the road intersection was “terribly confronting and tragic”.

“Such was the nature of the damage we’ve had to call disaster victim identification experts, and our search and rescue team, to try and investigate how many people were involved,” he said.

“That’s why I can only tell you, 24 hours later, how many people were involved.”

The crash about 2.30pm on Thursday involved two cars and a truck.

Police say they had intercepted a white Mercedes sedan at 1.45pm. Its 29-year-old driver was given a ticket for going 118km/h in an 100km/h zone in Strathmerton.

A short time later, the Mercedes collided with a Nissan Navara, which spun out and hit a fully loaded B-double milk tanker on the Murray Valley Highway.

All five people in the Navara died instantly.

Two other people involved in the crash, the 29-year-old Mercedes driver and his 29-year-old female passenger, were to hospital with minor injuries on Thursday.

They have since been released, and the Melbourne-based driver is in police custody. He is expected to face court in Shepparton later on Friday afternoon.

Assistant Commissioner Weir said he had watched footage from the truck of the incident.

“It’s horrific. It is catastrophic, the damage that has been caused as a result of a simple collision that has ended with the loss of five lives,” he said on Friday.

The Navara driver was a local woman, aged in her 60s. Her passengers – a man and three women aged in their 20s – are thought to have been visitors from Asia who were working for the Navara driver on a local farm.

“This is a really difficult and protracted investigation that will go on for a long time,” Assistant Commissioner Weir said.

“The ripple effect of this one tragic incident will remain for a long time.”

– with AAP