HOUSTON -- A gas station employee has been accused of running up a big bill for the United States Postal Service, KPRC Local 2 reported Tuesday.

Javed Iqbal, 36, has been charged with unauthorized use of an access device.

Federal investigators said Iqbal, an employee at the Susser Chevron station in the 14000 block of the Eastex Freeway, made about $87,000 worth of fraudulent charges to the postal service between March and June.

Officials said Iqbal made the charges to the postal service's Voyager card, a credit card used to buy gas for postal vehicles. Voyager is a commercial fleet card program with individual accounts assigned to each vehicle and a personal identification number for each employee.

Forty-five card numbers have been compromised, detectives said.

Investigators said the station submitted 815 separate charges for payment by the USPS, representing about 12 percent of the total charges for the Houston district. Officials said 194 of those transactions were entered manually, which was 79 percent of all the manually entered transactions in the USPS Houston district.

Many of the transactions were made when the employee with the corresponding PIN was either on leave or not on duty, investigators said.

Agents found a list of Voyager card numbers and PINs when they executed a search warrant at the store, officials said.

Iqbal was also found to be in possession of a stolen firearm, investigators said.