A secret cannabis farm growing 1000 plants has been found in the centre of Wolverhampton.
It was found by British Gas engineers when they entered the cellar of the Grand Post House in Lichfield Street on Tuesday 3 May.
The workmen called police officers who spent two days clearing the scene.
The plants are believed to have a street value of around £1 million pounds.
No arrests have been made in connection with the find, police said.
A spokeswoman for West Midlands Police said: "Around 1,000 cannabis plants were discovered in the cellar of the Grand Post House in Lichfield Street by British Gas workmen on 3 May. No arrests have been made."
A passerby who wanted to remain anonymous said “it beggars belief someone could do that in the middle of a big city centre and only just around the corner from the cop shop”
The find is minutes away from Bilston Street police station.
Forensic investigators and a specialist cannabis removal team were photographed removing bags from inside the building.
The former head post office is a Grade II Listed building. The building was most recently used by Wolverhampton University, until 2007.
Each cannabis plant is thought to have a street value of £1,000.
Cannabis factories are thought to pose a large fire risk due to the electricity needed to power the lights.