Sounds to me like its an engine management fault? Obviously it wont flash up the low oil any more because the low oil sensor is the thickest sensor in the whole car, and will only tell you when its low, not if their is a fault!
Short of that, may be a possibility of the turbo to have blown? friend had the same problem on his leon when he took a chunk out of his sump, and his oil drained very quickly, blowing his turbo but locking it so there was no air getting to the engine. just a possibility?