U.S. federal investigators are hunting incidents of Medicare fraud, using sophisticated computer technology to determine unusual patterns.

In one case, investigators found a patient who had reportedly undergone a diagnostic rectal-probe procedure 118 times in a year at 21 medical facilities.

As one official told USA Today: "It's unlikely that could have occurred. This person would not have been able to sit on a plane."

The use of computer programs to find suspicious patterns is designed to help discover insurance fraud before payment.

Medicare investigators said they have also discovered cases in which improperly obtained Medicare patient identification numbers were used to bill for examinations that were likely never performed. Such discoveries have resulted in 83 diagnostic centers losing their Medicare billing privileges this year, with $163 million in payments denied.

Fraud is estimated to account for as much as 10 percent of the nation's $2 trillion healthcare spending bill.

Copyright 2006 by United Press International