Happened to me, the owner of the 2 houses I used to live next to gave one to his son and one to his daughter, they both let the houses out, using the council, they went on to use the two 3 bed houses to home asylum seekers during their application to stay, it was a nightmare as they had no respect for the property or anyone else
finally and I kid you not, they actually burnt the houses down cooking in a bedroom ! they did not understand how to raise the alarm by calling 999 !
There was nothing I could do even though I spoke to the father several times (he was on the council himself!)