US Secret Service files show the bigger the gang, the more money stolen.
The average cost of identity theft and resulting fraud in cases solved by the US Secret Service over a six-year period was more than US$31,000 (AUD$34,302), according to a study.
Research by the Center for Identity Management and Information Protection (CIMIP) looked at 734 cases with an identity theft component that were opened and closed by the US Secret Service between 2000 and 2006.
Of those 734, data was collected on 517 cases, as the others fell outside the modern interpretation of identity theft.
"The median actual dollar loss was US$31,356," said the report.
However, the amount of money stolen using identity theft rose depending on how many people were involved in the crime.
"The median loss in cases where the offender worked alone was US$22,526 (AUD$24,925)," the report said.
"That figure rose to US$42,710 (AUD$47,258) in cases with two defendants, and to $84,439 (AUD$93,432) in cases with five."
The amount of money stolen varied from 34 crimes with no dollar loss to US$13m (AUD$14.39m) taken in a single case.
In 47 cases, the actual loss from the crime was not available to the researchers.
Information stolen from businesses such as service industries and retail or financial companies was responsible for 50 per cent of the identity thefts, according to data from 274 of the cases.
In a third of those cases, data was stolen by an employee.
"The most frequent type of employment from which personal identifying information or documents were stolen was retail, including stores, car dealerships, gas stations, casinos, restaurants, hotels, hospitals, and doctors' offices."
The report called for business and government agencies to work together to solve the problem.
"Law enforcement should continue to share the information they find with corporate entities, such as the financial services industry, so that prevention and detection strategies can be enhanced," the study said.
The research was authored by Gary Gordon, professor of Economic Crime Programs at Utica College; Donald Rebovich, associate professor and chair of Utica's Economic Crime Investigation Program; Kyung-Seok Choo, assistant professor and chair of Utica's Criminal Justice Program; and Judith Gordon, program administrator for CIMIP.
The report marks the first time the US Secret Service has allowed its closed case files on identity theft and fraud to be reviewed.