The special inspector general for Iraq reconstruction is investigating more than $340 million in government payments that may indicate criminal activity.

The IG's forensic audit team reviewed 73,000 transactions worth $28 billion and identified more than $340 million worth of the transactions involving 800 vendors as "anomalous," according to the special IG Stuart Bowen. These could include duplicate payments, payments to a fictitious vendor, multiple payments to one vendor on the same date, or payments made at odd times, such as before the invoice due date.

The invoices reviewed to date cover approximately 80 percent of the $35.2 billion spent on Iraq reconstruction between fiscal 2003 and 2008. The anomalous expenditures represent nearly 1 percent of the spending during that period. More than $50 billion has been appropriated for the projects.

It is not clear how many, if any, of the anomalies are the result of waste, fraud or abuse, but "we expect that many of the transactions will prove to be proper," Bowen wrote. For example, there may be a legitimate reason to place multiple orders with the same vendor on the same day, he said.

Since starting the forensic auditing effort in December 2008, the IG's office has opened 27 criminal cases involving 36 people or organizations. The report provided no details on these cases because they are ongoing, Bowen said.