Properties at Tatura and Strathmerton were searched on Thursday, July 3, as part of a police investigation into drug trafficking.
Officers from Viper Taskforce, Public Order Response Team and the Clandestine Labs Squad executed six search warrants at locations in the two towns, as well as others in Wallan, St Albans, Tullamarine and Keilor Downs.
During the search warrants, officers located and seized items including more than 2kg of methamphetamines, about 4.5 litres of the drug 1-4 butanediol (GHB), and a quantity of amphetamine.
They also seized about 800 litres of herbicide and a number of other chemicals, ammunition, about $2000 cash, and a taser.
Police did not make clear exactly what was found at the Tatura and Strathmerton properties.
Investigators also seized a dismantled clandestine laboratory at the St Albans property.
A 46-year-old man from Keilor Downs was charged with trafficking a commercial quantity of 1-4 butanediol.
He was bailed to appear before Melbourne Magistrates’ Court on Wednesday, July 9.
A 39-year-old Wallan man and a 55-year-old St Albans man were both released pending summons.
A 31-year-old St Albans man was arrested, before being released pending further enquiries.