Department S - Season 1 Episode 10
The Treasure of the Costa del Sol

LOCATION: The Costa del Sol, Spain DATE: July 31st A man goes scuba diving while his friend waits in the car. The man returns from the dive with a fish, and his friend shoots him. Before he dies he is able to return fire with a spear gun, killing the shooter. A policeman happens upon the scene and finds the divers catch: a plastic fish with $100,000 inside.