Three men and one woman with addresses in Peterhead have been released on bail after £11,200 of drugs was found on the A90 near Laurencekirk on March 3.
The men aged 39, 27 and 25 and 34 year-old-woman were arrested following the seizure of heroin, cocaine and other drugs last week.
They appeared before the Aberdeen Sheriff Court on Friday where they were released on bail.
The drug haul was part of an ongoing intelligence led investigation, Opertion Banook.
Speaking after the find PC Richard Cooper from the North Aberdeenshire Pro-Active Department said: “Police recovered a dealer quantity of heroin and cocaine along with a personal amount of Cannabis and Diazepam.
“I would like to thank the public for their continued assistance in regards to Operation Banook which has allowed Police Scotland to continue to detect and deter organised crime and drug dealing in the North Aberdeenshire Area.