Mystery surrounds the disappearance of six grams of cannabis from a Western Australian police station last week.
Internal affairs officers quizzed staff at the Fremantle police station over the weekend.
It's the second time drugs have vanished from the building, with $15,000 worth of cannabis also disappearing in 2004.
At the time, four senior police were transferred, but no charges were laid.
This time, investigators are trying to establish whether the drugs were stolen, if a key was used to access the room where they were kept, or whether the drugs fell from a bigger package earlier in the day.
- Fairfax Media