With tax filing season heating up, an aggressive Internal Revenue Service crackdown is targeting the growing problem of criminals who use stolen identities to seek tens of thousands of dollars in fraudulent tax refunds.

Acting IRS Commissioner Steven T. Miller said that a January sweep in 32 states and Puerto Rico identified 389 ID theft suspects, including 109 who were arrested. The number of IRS ID theft investigations tripled in 2012 and is focused on high-risk cities such as Miami, New York, Atlanta, San Francisco, Chicago and Los Angeles.

In 2012, the IRS says its investigations and in-house filtering systems prevented $20 billion in would-be fraudulent refunds, up from $14 billion the year before.

Florida tops the U.S. in identity theft complaints at 178 for every 100,000 residents, according to the Federal Trade Commission.

- Associated Press