An Untidy Death by Simon Brett

This is the second book in the Decluttering Mysteries series. 

Declutterer Ellen Curtis is approached by Alexandra Richards who requests she meets with her mother to help sort out her flat which is full of newspapers.  Alexandra does not seem to like her mother very much and says to Ellen 'My mother's going to kill herself, that is if I don't kill her first'.  Ellen visits and gets on really well with Ingrid who used to be an actress.  Ellen then discovers that there has been a fire at the flat and Ingrid is now dead.  She is asked by the police whether or not she would have considered the flat to be a fire hazard as the old lady chain smoked.  Ellen seems to have been manipulated into a situation where she is being used to confirm the flat was a hazard.  Ellen is not so sure.  Ingrid was very clear that she was careful about her cigarettes and valued and took care of her life.  

The police seem to be disregarding the fire as an accident.  Ellen is not sure that it was and starts her own investigation into what could have happened as she is suspicious about the nature and timing of the death.