Police discovered more than half a kilo of cocaine, worth about £20,000, when they entered a flat in Birchgrove Crescent, Brighton, on Thursday, October 14.
Sussex Police has released details after two officers went to the flat at 7pm following an investigation into a street robbery in Western Road on October 2, when cash was stolen.
The officers were prevented from entering and forced their way in.
Two men ran from the scene leaving the large quantity of cocaine in the flat.
A 20-year-old man was arrested for robbery and possession with the intent to supply cocaine and has been bailed.
Sgt Julian Deans said: “When we forced entry to the flat we found more than half a kilo of cocaine in the process of being cut.
“The two men who fled are known to us and we are actively seeking them.
I would urge them or anyone who knows them to come forward.”
Anyone with information can contact police on 0845 6070 999.