Invoice matched to incorrect receipt

Hi

Invoice 1110370165 is matched to receipt 94024 po 5000051351 release 7 at 4000 qty and invoice 1110391099 is matched to receipt 101169 po 5000051351 release 7 as well at 4000 qty putting the qty billed at 8000 on the second invoice.

The second invoice has been incorrectly matched. User should have matched it to PO 5000051351 release 10.

This has now therefore casued a Qty ord hold on the invoice.

How can I 'unmatch' this second invoice from the incorrect PO and receipt?

Assistance would be appreciated

Thanks