Letting agents making routine checks on properties have been instrumental in helping to bring drug offenders to justice.
One man has now been sentenced to seven years in prison, and the other to five years and seven months after one of the biggest cases of its kind.
Huge amounts of money were involved in dealing cocaine and cannabis.
Police say that the investigation, in Plymouth, had an “unusual and fortuitous” break in August when a letting agent carrying out checks on a property found nine suitcases open in an empty living room.
Inside were bags smelling of cannabis.
Police found other evidence in the property, which had been rented out but showed no signs of having been lived in.
Neither of the men who have now been convicted were on the tenancy agreement.
Another rented house was raided, where detectives found more drugs, and this time over £10,000 in cash.
By chance, that same day, the team received a call from another suspicious letting agent who had gone into yet another property and realised something was not right.
Again, more drugs were found at this address, and a further big amount in cash – £41,219.
As part of Operation Othello, investigators suspected that the cannabis was being delivered to the rental addressed by members of a Vietnamese crime group.
Det Insp Paul Weymouth said: “We rely on the information from members of the public, from business people like letting agents, to alert us to their suspicions.”