Could be the fuel pump. Happened to me once. To check if the fuel pump is faulty, try this.
- Gain access to the fuel pump (it is at the back of the boot. you have to take out the "partition". It is at the far right side of the batteries.)
- Unscrew 4 screw to the pump cover plate
- Get a "malet hammer" - the rubber type, and start knocking at the to of fuel pump while someone keep cranking the motor. If it starts, fuel pump faulty.