Avensis lll 2.2 T180 2009 D-Cat 'Catastrophic' DPF failure?

[MichaelPC1]

Hi. My first post on here as I've just had / am having a major issue with my car. I had to pull up suddenly last week with clouds of white smoke suddenly pouring out of the engine. I think it was from the bonnet area, but so much I couldn't be sure. Car limped and engine ran for a very short time, then stalled. It briefly restarted, but with immediate clouds of smoke and rough running. I got a couple of codes off the OBDll with a reader I have, P0200 Injector Circuit Malfunction and B1313 Battery Saver Relay Coil Circuit Failure? On the dash I got engine management light and wording 'Check parking brake system'. All seem a bit random really. The car is fully serviced and has done less than 2000miles since a 'clean' MOT pass end of Nov, including 6 trips of 200 miles a piece at motorway speeds, spread throughout that time. 

Car will most definitely not start now, but all systems that have been checked by mechanic are good, i.e. Camshaft turns, so chain appears intact, Fuel is getting pumped to rail. No fluid loss apparent from coolant, and no fluids leaking from anywhere that can be seen.

The mechanic I had come around removed some pipework and showed me what he said was exhaust gas coming straight back to EGR, which he said, (along with some unusual readings his decent OBDll set-up showed), was due to a 'blocked' DPF filter.

There was no lead up to this failure, No DPF warning lights, (does this car have one!), I've rarely noticed any smoke save for under hard acceleration on a few occasions, and this no more recently than since I've had the car.

My question is, has anyone experienced this rapid failure? In talking to a garage who should be looking more at this next week, I wonder if there is a possibility that, rather than the actual DPF filter gradually clogging up with soot, the integral Cat, (which I believe is within the same part as the DPF on the D-Cat engine?), has physically collapsed and caused the blockage?

Any thoughts and ideas greatly appreciated - especially if anyone knows how to get hold of a reasonably priced DPF/Cat!!

Michael