Eagle eyed staff at the Royal Mail have prevented drugs getting onto Peterborough streets - after stopping a suspicious package being delivered.
The Peterborough workers found packages of drugs in the mail as they were sorting through the undelivered post.
They raised concerns with police, who uncovered the packages.
Cambridgeshire police have praised the Royal Mail staff after they were called to the Royal Mail offices in Papyrus Road, Werrington, at 3.45pm on Tuesday, November 22.
The packages were discovered to contain small amounts of cannabis, cannabis resin and some tablets suspected to be illegal drugs
A Royal Mail spokesperson said: “Royal Mail does not knowingly carry any illegal items in its network.
“Where Royal Mail has any suspicion that illegal items are being sent through our system, we always work closely with the police and other authorities to assist their investigations and to prevent such activities from happening.
“For obvious reasons, we are not able to give any further details about our security measures.”
Police said investigations are still being carried out, including forensic work, but no arrests have yet been made.