Texas Department of Public Safety Texas law enforcement officers seized more than 3.9 tons of marijuana concealed in a tanker trailer on Tuesday.

What started out as a routine stop for a commercial vehicle inspection turned into a major drug bust Tuesday when Texas Highway Patrol troopers said they found 3.9 tons of marijuana concealed inside a tanker rig.

The value of the marijuana was estimated at more than $3.4 million, the Texas Department of Public Safety said in a news release Wednesday.

The driver of the 1999 tanker truck was arrested and charged with possession of marijuana. The name of the driver is being withheld, Sgt. Johnny Hernandez, a DPS spokesman said, because there is the possibility of more arrests in the case.

The amount of pot confiscated in the incident was among the largest in recent memory, Hernandez said. "It's a big, significant seizure," he said.

An investigation into the marijuana seizure, which took place in San Patricio County northeast of Corpus Christi, was continuing on Wednesday, according to Texas officials.