Washington (CNN) -- Government auditors said Monday they are launching an investigation into possible misuse of government-issued purchase cards at the U.S. Department of Transportation.
The department's Inspector General's Office said the audit of employees' use of the "SmartPay" purchase cards follows the conclusion of two cases that "have revealed control weaknesses" within the Federal Aviation Administration.
Department employees used the cards to buy more than $200 million in products and services in fiscal 2010, the office said.
It said it aims to complete the investigation in 10 months to a year.
In the two FAA cases, employees used the cards to buy more than $150,000 in goods and services for their personal use.
In the most egregious case, Keysha Logan, an assistant in the FAA's Finance Services Comptroller Group, used the purchase card to buy retailer gift cards, kept the gift cards for her personal use and then used the FAA computer system to approve the government's payment for the charges.
The scheme cost the government $123,774.47, according to the department's Inspector General's Office.
Logan was sentenced in February to four months of prison and four months of detention, to be followed by three years of supervised release. She also was ordered to reimburse the government.
In an unrelated case, former FAA employee Sabrina Vines pleaded guilty in 2008 to theft after investigators determined that she used her government purchase card to buy laptop computers and high-definition televisions, and to pay for rental car and hotel transactions at a Myrtle Beach, South Carolina, resort. The losses exceeded $23,000, the Inspector General's Office said.
Both women were fired from the FAA, the office said.
The Department of Transportation issued a release saying it welcomes the review.
"The department's use of purchase cards is based on strong training, systematic controls and multiple levels of review that we believe offer cutting-edge purchase card management," it said. "The program only stands to benefit from the type of careful objective review we anticipate from the Office of Inspector General."