Inconsistency between FB03 and BSEG

Hello All,

We have an issue  that some of the Fi documents were deleted.But the doucment was posted through an IDOC from another system.

Problem is when we check the documents in FB03 the line item data is missing but in BSEG the line item data is available .Because of which we are having the differences in the ledger balance at GL and SL level.

So please help us on this issue why there is a discrepency between FB03 and BSEG and how to avoid it.

Thanks in Advance.