The son of a famous Mexican mariachi musician charged with trying to smuggle four undocumented Chinese nationals crammed in the trunk of his car across the U.S.-Mexico border into San Diego has pleaded not guilty.

Jose Emiliano Aguilar, the 24-year-old son of Grammy Award-winner Pepe Aguilar, was arrested by U.S. Customs and Border Protection officers on March 14 at the San Ysidro border crossing and charged with human smuggling.

At his arraignment Thursday, he entered a not guilty plea to a federal charge of human smuggling through his San Diego-based defense attorney, Jeremy Warren.

The family thanked fans for the outpouring of support they received in recent weeks in a statement issued through Warren.

"The Aguilar family is grateful for the outpouring of love and support from thousands of people in the United States, Mexico, and all over the world. They are united and strong and they stand by their son Jose Emiliano. They thank everyone for their kindness and understanding as the case progresses," read the statement.

Jose Aguilar allegedly arranged to smuggle the immigrants into the U.S. under a deal in which they would each pay him between $3,000 and $60,000 if they successfully entered the country, according to a complaint filed in federal court.

The complaint said Jose Aguilar drove through a border checkpoint just after 5:45 p.m. on March 14 in a Chrysler 200, accompanied by a woman in the passenger seat.

Aguilar, who is a U.S. citizen, showed his passport to border agents, while his passenger showed officers her border crossing card, according to the complaint. Aguilar allegedly told officers they were headed to San Diego and had nothing to declare from Mexico.

During a routine primary inspection of the car, a K-9 dog alerted officers to the trunk. Officers told Jose Aguilar to unlock it, the complaint said. Inside the small space were four undocumented Chinese nationals, officials said, three women and one man. Aguilar and his companion were detained while border agents removed the people from the trunk.

They were questioned as "material witnesses" and, according to documents, admitted they were citizens of China without lawful documents to enter the U.S.

Each had made their own smuggling arrangements with Jose Aguilar, agreeing to pay him to help them get into the U.S., according to the complaint. Two of the Chinese nationals said they planned to head to Los Angeles, while the other two said they were headed to New York City.

A document filed in the U.S. District Court Southern District of California shows Aguilar was released on a bond of $15,000. His bond conditions include that he not travel to Mexico and that he not possess any drugs or firearms. He must also report to supervision to a pretrial services agency.

Additional conditions outlined for Jose Aguilar include that he must undergo psychiatric or psychological counseling, he must "actively seek and maintain full-time employment, schooling, or combination of both," and must live with his mother. He must also surrender his passport and cannot apply for new travel documents.

Previously, Warren confirmed Jose Aguilar's relation to Pepe, but said this case has nothing to do with the mariachi singer. The attorney released this statement to NBC 7: "We understand the interest in our client Jose Aguilar because of his father’s musical career. However, this case has nothing to do with Pepe Aguilar. Jose Aguilar is young man who will address this matter in court, and not in the press. We understand that Pepe Aguilar will provide a statement shortly. In the meantime, we ask that you respect the family’s privacy."

The prosecutor in this case, Assistant U.S. Attorney Blanca Quintero, told NBC 7 the U.S. Attorney's Office would not be commenting any further at this time.

Aguilar is scheduled to be in court next on May 15.