Audi s5 starter motor relay location

Morning everyone. Unfortunately this has been a long arduous task. Clutch pedal went straight to the floor at Xmas time. Searched the web and thought it could be the master cylinder. So renewed it. No luck. Renewed the slave cylinder. No luck. Brand new clutch flywheel trust bearing. Finally got that sorted. In the mean time the car decided not to start. Key was not wanting to pop back out of dash. Had that sorted. Now it's decided to do the same thing again with key. My mechanic looked up faults with diagnostic reader. It's saying starter motor relay. I've checked all fuses. Checked the 3 relays above the master cylinder and the one below the steering wheel. Can anyone point me in the right direction for a starter motor relay. Or maybe it's something to do with key. I've also put a new starter motor in the car last October and a new battery. Any help here would be greatly appreciated.