A 44-year-old man from D’Abadie was arrested during an anti-crime exercise conducted in the Northern Division on Tuesday.
Officers were proceeding east along Robin Terrace, Maloney Gardens, when they observed a man standing on the southern side of the road.
He ran in the opposite direction after seeing the officers.
He was held a short distance away after a brief chase.
A transparent plastic bag containing 19 grams of rock-like solids resembling cocaine along with three rounds of nine millimetre ammunition was allegedly found after the man was searched.
He was subsequently arrested and conveyed to the Maloney Police Station.
Investigations are continuing.