HAMMOND | Two years ago, Fernando Sanz and Thomas Prieto were sitting in the back of a police car, talking in Spanish as they watched a Lake County police officer search their car for drugs.

Whether they knew the Honda held 8 pounds of methamphetamine in hidden compartments will be a question for a jury to decide next week. But it's clear the duo did not know their conversation in a squad car was being secretly recorded, Hammond federal court records state.

"They discussed the fact that they were 'screwed' and wondered whether the narcotics in the front bumpers would escape detection," court documents filed by prosecutors in the case allege.

The existence of the recording system inside the police car was disclosed in court paperwork filed Tuesday, and attorneys on both sides of the case expect the recordings to be central to the trial. Police said the Aug. 26, 2005, bust was the largest meth traffic stop in Lake County history.

The officer who made the traffic stop was Lake County Deputy Cmdr. Oscar Martinez, a veteran officer well known for making large drug busts on Interstate 65. Martinez heads the Lake County Drug Interdiction Unit.

Court filings say his car is outfitted with recording equipment that can capture conversations inside the passenger cabin and outside on the road, where other recordings in the Sanz-Prieto case were made.

Jury selection is scheduled to begin Monday. The attorney for Sanz could not be reached for comment.

Adam Tavitas, attorney for Prieto, said he intends to argue his client -- who was the passenger -- was not responsible for the hidden drugs in the Honda Civic.

"It was not (Prieto's) car. There were no drugs on his person or any money," Tavitas said.

Inside the police car, Prieto and Sanz were recorded discussing efforts to get their story straight and expressing alarm as Martinez came steadily closer to the drugs hidden in compartments in the car's bumpers, prosecutors allege.

Tavitas said he hired a translator to decipher the recordings on behalf of the defense.