Missing plug/screw in block?
 

While my son was replacing his oil pan gasket on his 08 R56, he found a stud/set screw/plug sitting on the undercarriage cover, loose and rolling around. He wondered and worried about it, but couldn't see where it came from. He finished the job, and the next day the car was leaking oil. The new gasket worked great, but he found a threaded hole on the end of the block, below and to the rear of the front main seal, just above the pan, that was wide open and leaking. Does anyone know what the thread size, part number, etc. is for the missing plug? I cannot find it in any diagram. See photo of the location (using file photo). Thanks!!!!

https://cimg7.ibsrv.net/gimg/minicoo...99dbc45cca.jpg