A NSW transport company and three men have been charged over a crash that killed four police officers on a Melbourne freeway.

Leading Senior Constable Lynnette Taylor, 60, Senior Constable Kevin King, 50, and constables Glen Humphris, 32, and Josh Prestney, 28, were killed while on duty on the Eastern Freeway at Kew on April 22, 2020.

The crash was the single greatest loss of life in Victoria Police’s history, with the truck driver responsible jailed for 22 years earlier this year.

Victoria Police on Tuesday said more charges had been laid following an investigation with the National Heavy Vehicle Regulator.

A transport operator located in Riverstone, NSW, a 51-year-old man from Kenthurst, NSW, a 47-year-old man from Glenwood, NSW and a 52-year-old man from Labrador, Queensland, were charged with Category 1 and 2 offences under the Heavy Vehicle National Law.

According to police, Category 1 offences carries a maximum penalty of $300,000 and/or five years imprisonment for an individual and $3 million for a corporation.

Category 2 offences carry a maximum penalty of $150,000 for an individual and $1.5 million for a corporation.

The matter will next be heard at the Parramatta Local Court in NSW on September 28.

-AAP