Remove Duplicates Within Pipeline

I have a situation where we get XML files sent daily that need uploading into SQL Server tables, but the source system producing these files sometimes generates duplicate records in the file. The tricky part is, that the record isn't entirely duplicated. What I mean, is that if I look for duplicates by grouping the key columns, having count(*) > 1, I find which ones are duplicates, but when I inspect the data on these duplicates, the other details in the remaining columns may differ. So our rule is: pick the first record, toss the rest of the duplicates.

Because we don't sort on any columns during the import, the first record kept of the duplicates is arbitrary. Again, we can't tell at this point which of the duplicated records is more correct. Someday down the road, we will do this research.

Now, I need to know the most efficient way to accomplish this in SSIS. If it makes it easier, I could just discard all the duplicates, since the number of them is so small.

If the source were a relational table, I could use a SQL statement to filter the records to remove the duplicates, but since the source is an XML file, I don't know how to filter these out in the pipeline, since the file has to be aggregated to search for dups.

Thanks

Kory