2001 Fiat Ducato V8 Two Wheel Drive Manual 161000 miles

Hi I have a Fiat Ducato long wheel base High top 2.8 transit van. I went to start it today and there was a popping noise and then it wouldnt start although it turns over. It souded like the fan belt snapping at first which I checked and it wasnt. Later today I noticed that there was oil all over the floor under the front of the van. I have just been and checked where it is coming from and its stopped leaking but its all over the underneath of the van. I checked the oil filter which is in the area and is covered in oil but it is not that that has broken or leaked. on top of the oile filter drum I have found a large chunk of metal! I can only presume that its something major which has ripped out of something and I am fearing the worst it being a chunk out of the engine. Please does anyone know what it can be please? Thanks Liz