I have had a terrible smell in my house for at least 6 weeks. It smells like cabbage/rotten veg and it is unbearable. It was really bad and then it seemed to disappear, but now it's back with a vengeance.

The smell is worst in the study and at the front door in the hall, also in a small toilet that we have. All three of these areas have a common wall. My patrner thinks it might be because our house is not built far off the ground, i.e the front door is on ground level, but I am not so sure.

The house is only 14 years old.

There are no drains in the affected area that I know of.

It is not a sewage or gas leak smell.

I have checked the guttering and there is no blockage.

A plumber came out and checked under the floor and there was no sign of any leakage or plumbing problems, or dead animals.

The chimney appears to be clear of dead animals and is nowhere near the area where the smell is worst.

There are no physical signs of dampness or water anywhere that I can see.

I have had a lot of bluebottles in the house recentlyand I have no idea where they are coming from.

I swear, I am at breaking point over this problem. I have turned the house upside down looking for a dead mouse or something but I can't find a thing!! I don't think it is related to a kitchen appliance as the kitchen doesn't smell. I contacted Environmental Health who were worse than useless. If there was a dead animal in a wall cavity how would you know, and how do you deal with it? I don't even know if that's what it is. Why would the smell last so long if it was?

Please, anybody, what can I do? Who do you call to diagnose such a problem? I can't live like this!! :(