Further to my earlier post on this topic, I have spotted an interesting item on the BBC News web-site. This gives more information about the signs to spot a cannabis factory, and is well worth reading, plus there is an informative video.
Generally though landlords need to do regular inspections, and if a tenant consistently refuses to allow access, this should alert you to the possibility of criminal activity. If you just ignore the signs, you may have problems claiming for any damage later, on your insurance.
Also, if you are a landlord, it might be an idea now, to check to see whether this sort of thing would be covered on your current policy.
Most reputable landlord insurance policies would cover damage caused by illegal drug cultivation.This is subject to the property owner taking reasonable precautions to identify their tenant. The easiest way to do this is to obtain a comprehensive and independent reference on them from one of the many firms offering this service. You should also be wary of accepting advance payments for rent in cash as this may indicate that the person does not wish to disclose their history.
Thank you Robert. Just so people know, Robert is a director of the Alan Boswell insurance group, which specialises in insurance for landlords. So he knows what he is talking about!