Drugs and a number of weapons including grenades have been seized during a police raid on an alleged safe house in Sydney’s south-west.

Taskforce Falcon detectives, who investigate organised crime, made the discovery while carrying out a firearm prohibition order compliance check at a Glenfield home about 9am on Tuesday morning.

NSW Police seized six grenades, three semi-automatic assault rifles, four shotguns, a pistol, firearm parts, and more than 1,000 rounds of ammunition.

Two hands in blue latex gloves hold a metal-looking greande wrapped around the middle with fabric.

Police found six grenades at the Glenfield property. (Supplied: NSW Police)

A number of drugs were also found, including 15 kilograms of cannabis and 6kg of cocaine.

Police estimate the potential street value of the drugs is worth about $3 million. 

Electronic devices and $9,000 cash were also located.

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

A man in Nike sliders, black trackpants and a black shirt handcuffed sitting on a curb.

The 26-year-old man arrested has been denied bail. (Supplied: NSW Police)

The man was charged with 27 offences including possessing more than three unregistered firearms without licence/permit, and knowingly dealing with the proceeds of crime.

He has been refused bail and is expected to appear in court on Wednesday.

A woman in a high vis jumper with one police officer in front and behind her inside a police station.

A 26-year-old woman has been taken to Campbelltown Police Station. (Supplied: NSW Police)

The woman was charged with assisting at a drug premises.

She was granted bail and is expected to go before the court on August 27.