As the aux belt shreaded some of it may have been pulled into the timing belt,this causes the crank shaft pully to shear it's drive pin,this is a engine protection feature,.The timing belt and pulley will look fine and turn as normal, but as the pulley is not driving the crank shaft, and hence the valves the engine with not start.The solution is to buy a new pulley from renault and a timing belt and get it fitted
jkennedy, October 2008