Engine stopped suddenly - please help

[allankennedy]

My 2005 Audi Quattro 2.5 tdi Auto was running perfectly when suddenly, at  fairly high speed going uphill the engine cut out without warning.  No hiccups, no misfiring , just immediately stone dead. 
No warnings appeared  on the dash though when I was trying to restart I did see the glow plug light flashing at one point.
The rescue guy squirted something into the air intake and it started for a few seconds then nothing. From this he concluded that the engine is ok mechanically 

After being carried home I checked the fuel pump fuse then I loosened a pipe on the fuel filter and found that fuel is flowing when the ignition is switched on but with no amount of cranking will it even try to fire.

I should mention I have run the VAG.com engine  module which did not produce any fault codes . The car has done about 140k miles and had a cambelt change a couple of years ago. Present usage of the car is very light as I am now retired. 

Any advice / guidance will be greatly appreciated -- thanks in advance