An audit of the Maryland Transit Administration has led to a Maryland Attorney General investigation, and as much as $475,000 in fares could be missing.
The audit found MTA did not keep track of keys that could access fares, and one was in the possession of an unauthorized employee.
The agency is taking "a number of proactive measures" to tighten security in the wake of the audit, said Jawauna Greene, an MTA spokeswoman.
Among the measures is changing the locks on the equipment that stores fares and greater oversight of revenue, she said.
Greene said MTA welcomed the attorney general's investigation.
The Office of Legislative Audits found the agency did not use reports from its automated fare system to ensure collections were deposited. As a result, the difference between fare records and deposits is $475,000 from March 2007 to June 2007, according to the report.
The MTA operates the MARC train as well as bus routes around the state, including one that connects the Shady Grove Metro Station to Frederick and Hagerstown.
The audit also faulted MTA for failing to perform timely preventive maintenance on buses and for underusing its fleet.
In his response, Transportation Secretary John D. Porcari agreed with the auditor's findings and said he has taken measures to correct them.