Sydney drug labs busted, gun seized: cops

A series of raids in Sydney have uncovered three clandestine drug labs, police say.

Officers allegedly seized chemicals used to manufacture drugs, as well as ice, cannabis and a gun during the raids at Castlereagh, Berkshire Park, Londonderry and Claremont Meadows.

Three men have been arrested including a 40-year-old man charged with manufacturing and supplying a large commercial quantity of a prohibited drug and knowingly dealing with the proceeds of crime.

A 35-year-old man was charged with manufacturing a commercial quantity of drugs, while a 36-year-old is facing possession and supply charges.

All were refused bail and are expected to face courts in Penrith and Fairfield on Friday afternoon.

The drug labs were inactive, police said on Friday, but crime scenes have been established at the homes in Castlereagh and Londonderry as investigations continue.