A landlord whose flat in Northampton was raided in a police sting has called the operation "a shambles".
Armed officers bashed down the door at a flat in St Michael's Road on July 24 as part of an ongoing operation targetting drug dealing.
But police were unable to find their suspect, and the first the landlord heard of the search-and-entry was when his terrified tenants rang to tell him "officers with guns" were in the flat.
The landlord, who asked not to be named, said: "My tenants called me saying that armed police had knocked the door in.
"They couldn't go to work or university that day. They're stressed out and asking if they can move out, which I understand.
"If the police had contacted me in the first place I could have helped them or saved them the trouble, because their suspect had left weeks ago."
The operation - which involved around 15 officers, four police vehicles and a helicopter - was reportedly part of the ongoing Operation Viper to tackle drug dealing.
Officers were equipped with stab-proof vests and semi-automatic weapons and used an "enforcer" battering ram to break open the door.
Several Northampton Borough Council officers wearing stab-proof vests were also on scene after the strike.
The landlord said: "They were there for over six hours searching the flat and my tenants could not enter the property.
"The whole operation was a shambles and a waste of taxpayers money. I have put a complaint in with the PCC."
A spokeswoman for Northamptonshire Police said: "Warrants are planned operations based on intelligence received from a number of sources and they rely on the element of surprise to get the best results. This is why we are unable to inform the occupants or owners of a property before enforcement action takes place.
“Although we didn’t find our suspect at the property at the time, this warrant was executed in partnership with housing enforcement officers from Northampton Borough Council who are now considering the next steps based on their findings.
“We are committed to protecting people from harm, taking drugs off our streets and bringing offenders to justice – warrants are a great way to do this and we will continue to take enforcement action where intelligence suggests crimes are being committed.”
A spokesman for Northampton Borough Council said: “Members of the Council’s Housing Enforcement Team visited the property as part of a criminal investigation.
“They executed a warrant of entry issued by the Magistrates Court and, based on their findings, are now considering the next steps.”