Police have thrown the book at a young man and woman after seizing millions of dollars worth of drugs, grenades, ammunition and guns at an alleged safe house.

Detectives made the find during a raid on a home in Glenfield, in Sydney’s south-west, on Tuesday morning.

Weapons including six grenades, three semi-automatic assault rifles, four shotguns, a pistol, firearm parts and more than 1000 rounds of ammunition were found at the scene.

Six kilograms of cocaine, a kilogram each of methylamphetamine and ketamine, 15 kilograms of cannabis, 1.1 kilograms of heroin and 107 grams of MDMA rounded out the drug haul.

The detectives, from organised crime, public place shooting and gangland violence specialist group Task Force Falcon, also seized electronic devices and $9000 in cash.

A man and a woman, both aged 26, were arrested and taken to Campbelltown Police Station.

The man was charged with 27 offences, including firearms possession and drug supply charges and knowingly dealing with the proceeds of crime.

The charges also included possession, supply or make explosive for unlawful purpose, deface identification mark on firearm/part and organises/conducts/assists drug premises.

He was refused bail to appear at Campbelltown Local Court on Wednesday.

The woman was charged with organises/conducts/assists drug premises.

She was granted conditional bail to appear at the same court on Thursday.

NSW Police Minister Yasmin Catley praised the efforts of police and said the bust should put wrongdoers on notice.

“It’s awful to think what could have happened if police hadn’t intervened when they did,” Catley said.

“To anyone thinking of taking part in this alleged vicious criminality, our message is be prepared to spend a long time in a small cell.”

State Crime Commander Assistant Commissioner Scott Cook said the seizure exposed the dangers posed by organised crime groups.

“The fact these items were located inside an alleged safe house shows the level of violence these groups are prepared to engage in, and the level of risk they pose to the public,” he said.

“We will continue to target these networks relentlessly. Anyone involved in organised criminal activity should expect Taskforce Falcon to be at their door.”

–AAP