Did a data breach lead to fraudulent tax filings?

The Federal Bureau of Investigation has started an investigation into fraudulent tax returns filed using the popular TurboTax software.

"The FBI is aware and investigating the matter," the agency said in an email to CBS MoneyWatch. "That is all that we have available right now because we cannot comment further on an ongoing investigation."

The probe is seeking to determine whether a computer data breach allowed fraudsters to file fake tax returns for taxpayers through TurboTax, according to The Wall Street Journal, although it's unclear where the potential breach occurred. Intuit (INTU), TurboTax's parent company, said it has not been notified and is not aware that it is the target of an FBI investigation.

Fraudulent tax filing is on the rise in the U.S., a crime that was highlighted last week when TurboTax temporarily halted filing state tax returns after noticing a rise in the crime. In such instances, criminals submit tax returns for other people, using stolen Social Security numbers and employer information, and direct the IRS or state treasury departments to deposit the refunds into their own accounts. It's a crime that's costing taxpayers as much as $5.2 billion.

The issues may reach federal returns as well as state tax returns, with about 19 states seeing an uptick in fraudulent filings. The FBI is looking at whether information may have been stolen from TurboTax or elsewhere, with The Journal adding that some fake returns include information from 2013 tax returns.

"After working with third-party security experts on a preliminary examination of recent fraud activities, Intuit believes that these instances of fraud did not result from a security breach of its systems," Intuit said in a statement sent to CBS MoneyWatch.

Consumers are sometimes alerted to the fraud when they file their own returns and are informed by the IRS or their state tax department that their returns have already been filed. This can be the start of a major headache for victims.

The first step for victims is to file an identity theft affidavit with the IRS. While the agency wants victims to then continue to pay their taxes and file their tax returns, refunds may be delayed by as long as a year. That can be tough on taxpayers who rely on their annual refund to make ends meet.

Filing fake tax returns is becoming more popular with fraudsters because it allow them to get quick access to cash, with some directing the IRS or state agencies to deposit the refunds on pre-paid debit cards.