Recently in Portugal laws about steroids changed.
A policeman can enter a gym, pic a juicehead working out and force him to open his locker for a steroid search. If he has them he will face a trial wich can lead him to a maximum of 6 years in jail. About the same as if he was dealing narcotics.
Police can also take him for blood analisis but if he tests positive i don't know what kind of penalty occurs.
In reality i seriously doubt cops will do this because they also use and need dealers for their supply.
from one portuguese to another:
the gyms i have been to in portugal do not have lockers with name tags . how the fuck can the police know which one is your locker. Hell you just walked in from the street and started lifting- so what