PSNI officers have arrested a 31-year-old man on suspicion of supplying heroin and diazepam in Belfast city centre on Tuesday afternoon.
The suspect is being interviewed at Musgrave Police Station.
Detective Inspector Andy Dunlop said: "We have recovered a sizeable amount of heroin today and prevented potential harm to many people.
"I appeal to people to report any suspicious activity to the police. If you report it, we will respond."