Why is my imobilliser light flashing on my clio?

I have a 53 plate Clio dynamique 1.4 and the imobilliser light keeps on flashing when the engine is off and the key out of the ignition. I have 2 keys and it does it with both of them. I read in the handbook that there could be a fault with the imobilliser and it advises me to contact a renault dealership but I was wondering if there is a way to fix it without having to spend out a tonne of money. Any ideas?