The Inland Revenue is at odds with a Government software supplier over the hunt for millions of "missing" tax records.
Edinburgh-based Data Services said it has trained officials at Department of Social Security offices in Preston to verify work on finding 5.2 millions of tax records that an internal Inland Revenue memo said were "missing".
But a Revenue spokeswoman said her department's officials had no knowledge of the company's involvement in this work.
The problems have arisen partly because of interface issues between systems built for the DSS and those used by the Revenue.
Data Services said its product, Audit Command Language (ACL), is being used in support of reconciliation work to locate the tax records.
In a separate move the Revenue issued a statement on its Web site denying that any tax records have gone "missing".
This Revenue statement on the Web was issued after Computer Weekly published details of a high-level internal briefing paper that refers to millions of employee tax and pay details as having gone "missing" (Computer Weekly, 20 July).
This week Data Services stood by its announcement. It insisted that it has trained officials at the Department of Social Security' offices on how to use ACL to support the verification of Inland Revenue's efforts to trace the "missing" records.
"Data Services Ltd have supplied the DSS with copies of their ACL software which will help to verify that the "missing" records have been correctly identified," said the company.
ACL said it uses raw data out of its native environment to compare and provide matches of information in seemingly incompatible databases, whatever the applications software, system protocols or hardware.
This technique means that a snippet of information may be all that is needed to locate other data about a person in different systems.
The software is used by the private sector to help identify fraudulent insurance claims, subscribers to cable television receiving more services than they are paying for, or local authority staff who may not have paid council tax.
It has also been used by the Child Support Agency to help track down "absent" fathers with outstanding maintenance debts. Other users of the software include the big five audit firms, HM Customs & Excise, Abbey National, BSkyB, and the Royal Bank of Scotland.
In the Revenue's case, Data Services said that ACL is not being used for the initial search of the "missing" tax files but in support of independent verification that the identification of absent records has been successful or otherwise.
The search for the "missing" tax records is focused on two entirely different systems, the National Insurance Recording System, built for the Department of Social Security by Andersen Consulting, and the Inland Revenue's Computerised Operation of PAYE.
Few if any tax records are likely to have been lost permanently. But an internal Revenue memo reveals that the number of "open cases" that are under investigation, many of them because of "missing 1998/99 pay and tax details", is nearly four times higher than two years ago.
Despite this disclosure, the Revenue's official statement on its Web site said that the number of open cases in the 1998/99 tax year is "no different in that respect from other years".
A Revenue spokeswoman said that any work being done by Data Services for the DSS was irrelevant to the reconciliation of files involving NIRS2 and COP. "The DSS has no involvement at all in this reconciliation project," she said.
However Data Services insisted that it has trained DSS staff on the work involved.