A Walterboro couple was arrested Wednesday after investigators said they drove a tanker truck off a National Guard base, drained several thousand gallons of diesel fuel and returned it nearly empty.

Clarence Edward Risher Jr. and his wife, Melinda Montjoy Risher, also known as Melinda Gail Risher, are both charged with grand larceny over $10,000. Both are 42 and live on Risher Mountain Road.

The M969A1 fuel tanker looks like a camouflaged version of those big tankers that carry gasoline along the interstate. It holds 5,000 gallons and had 3,600 gallons in it when it was taken from the base, according to Maj. Cindi King, public information officer for S.C. National Guard.

The tanker doesn’t require a key to start it, Colleton County sheriff’s Chief Deputy Ted Stanfield.

The tanker was stolen between April 26 and Monday and returned early Tuesday when nobody was around, Stanfield said. Deputies called the S.C. Department of Natural Resources for help, and the agency sent in an airplane and a ground crew on all-terrain vehicles to help track down what happened to the fuel.

The trail led to the Rishers, and a search of their properties led to the recovery of about 2,675 gallons of fuel and the seizure of a John Deere tractor, Stanfield said. The National Guard was called in to reclaim the stolen fuel, he said.

The investigation continues, and more arrests are possible, Stanfield said.

Clarence Risher was released from the Colleton County jail on $14,000 bail Thursday, according to court records. His wife was released on her own recognizance.