Four men have been charged after an alleged cocaine syndicate was busted on the NSW Central Coast.

Anti-gang squad detectives began investigating the group late last year, believing they were supplying drugs including cocaine to people on the Central Coast.

Officers raided a Berkeley Vale storage facility on March 15, seizing about 3.6kg of cocaine along with 3.1kg of cannabis, 500ml of GBL, 200ml of human growth hormone, drug paraphernalia and a money counter.

Police on Thursday searched properties in Ourimbah, Empire Bay, Berkeley Vale and Chittaway Bay, allegedly finding items including firearms, ammunition and motor vehicles, along with cocaine, heroin and cannabis.

Police said four men were arrested and charged with offences including supplying prohibited drugs and participating in a criminal group that contributes to criminal activity.

A 38-year-old Ourimbah man and 27-year-old Empire Bay man fronted the Gosford Local Court on Friday, while a 39-year-old Berkeley Vale man and a 38-year-old Chittaway Bay man appeared at Wyong Local Court.

All were refused bail and remanded to return to court either later this month or in May.

By Tara Cosoleto in Melbourne