Diesel Leak after turbo inlet valve replaced

My 3.5 year old, high mileage Dicovery 4, had a turbo inlet valve replaced by the main dealer. Three weeks later I had a massive diesel leak which I've been told (by another main dealer) is from the water sensor for the fuel.

Would the sensor have been disturbed when the turbo inlet valve was replaced?

Not sure what you mean inlet valve, do you mean a new turbo or just the actuator that bolts to it? Or non of those

Don't think it was a new turbo as turbos were replaced six month ago (along with new engine under warrenty). Was told the inlet valve and sensor were replaced.