Police Commissioner Edward Davis said the drugs, either stolen or improperly thrown away, include marijuana, cocaine, heroin and OxyContin, The Boston Globe reported. In some cases, OxyContin was replaced with a non-prescription painkiller.
The police department, FBI and Suffolk County district attorney have begun a join investigation. Only police officers can enter the central drug depository, Davis said.
The department began auditing drugs in 2006 because the drug depository was being moved from one part of the police warehouse to another. Davis said the original plan was to do a random sample of evidence, but a complete audit was initiated after some drugs were found to be missing.
Investigators found 265 envelopes showed signs of having been opened or had been completely emptied. In 700 other cases, envelopes were missing, either stolen or simply thrown out.
So far, all the missing evidence is from cases that have been closed.