U.S. Border Patrol (search) agent accidentally drowned moments after rescuing an immigrant from a swift-moving portion of the Colorado River, authorities said Saturday.

The body of James Epling (search), 24, was found in the river Friday, three days after he was last seen along a river trail near Andrade, Calif., just north of the Mexico border.

The Maricopa County Medical Examiner's Office performed an autopsy Saturday and found that Epling accidentally drowned, Border Patrol spokesman Joe Brigman said.

Epling had been chasing four suspected illegal immigrants (search) along the river Tuesday. He had pulled one of the immigrants, a Chinese woman, from the water shortly before he disappeared.

The agent was found within 200 yards of where he was last seen in 54-degree water about 27 feet deep, Brigman said. Divers used sonar and other high-tech equipment in the turbulent, cloudy water.

Epling is the seventh agent from the Border Patrol's Yuma sector to die in the line of duty in 36 years, Brigman said. The sector covers southwestern Arizona.

"Agent Epling exemplifies the definition of courage, honor and dedication," said Michael C. Nicley, Yuma sector patrol chief. "He is a true hero, having risked his own life to save others. We honor his courage and sacrifice."

Epling was a father of three, and his wife is expecting another child early next year.