Can my insurer put a claim on my policy just because it cost them to investigate?

My insurer investigated a claim someone had put in against me and turned it down flat. However, they've put a no fault claim on my policy. When I queried this they said it had cost them money to investigate...

A 'no fault' accident has left me without enough insurance money to repair my car - what are my rights?

Having suffered a "No Fault" accident, I cannot get the other driver's insurance company to repair my car. I own a 2002/2003 Volkswagen Passat 2.0-litre petrol saloon from new, with 59,000 miles and have...