The information is not available.
Information relating to outstanding overpayments, including that arising from fraud on the part of the claimant, of 2003-04 and 2004-05 tax credit awards is contained in part 2, table 11 of the report by the comptroller and auditor general, in the HM Revenue and Customs 2007-08 accounts. The publication is available on the HMRC website at:
http://www.hmrc.gov.uk/about/hmrc-dep-acct0708.pdf