This was an older question that a previous SME was unable to answer. Attempts to reach the question submitter for additional information were (unfortunately) unsuccessfuil.

There was not enough information in the question or question background to provide a concrete answer. Some of it has to do when did the contractor start invoicing, was it voluntarily disclosed, what specific data was it, etc., etc.

Therefore, the best we can offer is follow the guidance and requirements at FAR 15.407-1 Defective certified cost or pricing data and of course the DFARS 215.407-1.