HOUSTON -- Agents with the Houston Office of the Drug Enforcement Administration arrested three people, and seized cocaine and cash as part of an ongoing investigation into Mexican drug cartel operations in the city, KPRC Local 2 reported Thursday.

Court records obtained by Local 2 Investigates show Oscar Guajardo, Julio Garza and Patrice Green were arrested Tuesday following surveillance of a horse stable at 5400 Schurmier Street in southeast Houston.

DEA agent Violet Szeleczky told Local 2 the location was targeted as a possible drug stash house in 2007 during "Operation Three Star," an investigation that eventually led to the dismantling of three major drug trafficking cells using tour buses to shuttle cocaine and cash between Houston and Monterrey, Mexico.

"At that time, we found no drug activity at the location, but always kept the location in the back of our mind to continue checking," said Szeleczky.

Records filed in Houston federal court read that during surveillance of the property, DEA agents observed Garza placing a black bag in the trunk of Green's BMW.

Agents write they followed Green's BMW to a Valero gas station on South Post Oak Boulevard. Agents stopped the car and after getting a search warrant report, they found more than 16 pounds of cocaine and $20,000 worth of blank money orders inside the BMW.

In tandem with Green's arrest, agents said they maintained surveillance on Garza and Guajardo at another house at 613 Iowa in the city of South Houston.

A criminal complaint filed by the DEA reads that agents searched the home after observing Garza and Guajardo carrying a black bag inside. Court records show agents seized more than 25 pounds of cocaine and found more than $1.3 million in cash hidden under a child's bed in the house.

Agents write that Guajardo admitted he had been receiving instructions where to collect the money and drugs from a man in Mexico named "Cerillo."

Szeleczky told Local 2 the operation that led to these arrests focuses on tracking the activities of the Gulf Cartel. All three have been charged with conspiracy to possess with the intent to distribute cocaine.

State records also showed Green is the operator of Little Einsteins Academy on Cook Road, which is listed a licensed day care center for infants, toddlers and pre-kindergarten children.