WASHINGTON (AP) — The IRS says thieves used an agency website to steal tax information from as many as 220,000 additional taxpayers.
The agency first disclosed the breach in May. Monday's revelation more than doubles the total number of potential victims, to 334,000.
The thieves accessed a system called "Get Transcript," where taxpayers can get tax returns and other filings from previous years. In order to access the information, the IRS said the hackers already had information about the taxpayers, including Social Security numbers and dates of birth.
The IRS believes the breach was part of a sophisticated scheme to use stolen identities to claim fraudulent tax refunds in future years.
The IRS said it will begin notifying newly discovered victims in the next few days. The agency will offer credit protection.