Authorities have seized 15 kilograms of heroin from an Adelaide property, which is believed to be the largest single seizure of the illicit drug by SA Police.
Serious and Organised Crime Branch officers also found one kilogram of cocaine in packages at the Stuart Street, Angle Park property.
Another home in Mansfield Park was also searched by officers who found cash and equipment, which they will allege was used in the preparation for the sale of heroin.
Detective Chief Inspector Christina Buckley said residents at one of the houses were interviewed but no arrests had been made.
She said the drugs would be worth several millions of dollars.
"Police will continue to tackle organised crime groups, who are involved in the importation, manufacturing and supplying of illicit drugs," she said.
"We are committed to the reduction of the harm caused by the use of illicit drugs in our community."
But police said they did not believe the haul was connected to bikies.
"[It's] wonderful that we have taken this amount of drugs off the street, [it's] not only a good result for the police but a good result for the community," Chief Inspector Buckley said.
Anyone with information is asked to call Crime Stoppers on 1800 333 000.
