ROUND ROCK — A Williamson County sheriff’s detective seized $33,000 during a traffic stop on Interstate 35 in Georgetown, according to an arrest affidavit.

Juan Bautista, 29, of Laredo, was charged with money laundering, a third-degree felony punishable by up to 10 years in prison.

A detective stopped Bautista in the 4600 block of Interstate 35 South on Jan. 13 because Bautista was driving a Ford sedan in the left lane but not passing anyone, the affidavit said.

Bautista told the detective he was driving home to Laredo from Pecos, the document said. It said Bautista said he had been working in the oilfields in Pecos for three months.

It said the detective found out that the license plate of Bautista’s car had been recorded in Austin on Jan. 10, which contradicted Bautista’s story about where he had been.

The detective then got Bautista’s permission to search the car and found seven bundles of cash behind the carpet lining of the trunk, the affidavit said.

When the detective asked Bautista how much money was in the trunk, Bautista initially said $10 to $15 but then later said there was $33,000 in it, according to the document.

Bautista would not tell the detective where the money came from, the affidavit said. It said the detective also found receipts from Jan. 12 and Jan. 13 in the car from businesses in Kentucky and Greenville, Texas, that contradicted what Bautista said about where he had been.

Bautista was being held Wednesday in the Williamson County Jail with bail set at $50,000.