It's a growing problem around the United States -- criminals have figured out how to chemically wash the ink off of $5 bills and reprint them as $20, $50 and $100 bills.

Now the crime has come to Batavia.

Det. Kevin Czora said that nine local businesses have been hit by bogus $50 bills. He expects more reports to come in.

It's early in the investigation, Czora said, so he doesn't yet have a total of how much fake currency has been passed in the city.

The bills get by some employees and shop owners because they will pass a pen test -- they are, after all, printed on legitimate U.S. currency paper.

The fake bills, however, are not completely undetectable. There remains a security strip embedded in the bill that says USAFIVE.

The U.S. Treasury Department also maintains a Web site with information on currency printing and how to detect fakes.

One alleged counterfeiter in the Dallas-Fort Worth area reportedly said he produced more than $10,000 in fake bills.

He even bragged about how good the bills looked.

"These bills here are good enough that I think they could have passed," Runge said. "Some of these bills will stay in circulation for quite a while."

A Google search shows that such fake bills are showing up all around the country. There was an arrest recently in Buffalo of a person who allegedly used a fake $50 bill, but the Buffalo News story doesn't mention whether the bill was a washed $5 bill or if some other method was used.

Det. Czora said businesses owners and employees should be extra vigilant when accepting large denominations and to report any suspicious transactions to the City of Batavia Police Department at 345-6350. Descriptions of suspects and their vehicles should be reported as soon as possible to assist the investigation.

Photos: Above, one of the fake $50 bills passed at a local business; below, a surveillance-camera picture of a subject wanted for questioning in the case.