SEATTLE — The father of an American wanted for ecoterrorism attacks in the western United States said Saturday that his son was sentenced to prison in China after pleading guilty to drug charges in that country.

Justin Franchi Solondz, 30, was sentenced Friday at a court in Dali, a city in southwestern China’s Yunnan province, according to Chinese and American officials. His father, Paul Solondz, said his son pleaded guilty last month.

Solondz told the Associated Press that Justin was arrested in China during a drug sweep in March, and authorities later found 33 pounds of marijuana leaves buried in the courtyard of a home he rented.

Justin, a former student at The Evergreen State College in Olympia who grew up in Randolph, N.J., was indicted in California and Washington state in 2006 in connection with a series of arsons attributed to “the Family,” a collection of radical environmentalists aligned with the Animal and Earth Liberation Fronts, from 1996-2001.

Attacks by the group caused more than $80 million in damage, according to the FBI, which called Justin a domestic terrorist. Prosecutors say he used timers, plastic containers and fuel-filled bladders to build incendiary devices used in one of the most notorious blazes, the May 2001 destruction of the University of Washington’s Center for Urban Horticulture.

Investigators heard little of Justin after his indictment, and the FBI issued a $50,000 reward late last year for information leading to his arrest. At the time, the agency said he might be in Canada, Europe or Asia.

Early this year he surfaced in Dali, a city popular with Western tourists, using fake Canadian identification and an altered appearance, said Mark Bartlett, the first assistant U.S. attorney in Seattle.

After Justin was arrested in the drug investigation in March, federal prosecutors in Seattle were contacted to help confirm his true identity, Bartlett said.

The U.S. has no extradition treaty with China, and it’s not immediately clear when or how Justin might be returned to the U.S. to face charges, Bartlett said. The Justice Department has informed Chinese officials that it remains interested in prosecuting him.

“We did not want to be seen as interfering, so we were letting the legal process go forward there so he can face the music there,” said Seattle FBI spokeswoman Robbie Burroughs. “When he gets back here, we’ll deal with him.”

Paul Solondz said his son did not flee the U.S. to avoid prosecution. He said Justin went to Italy for a wedding in 2005 and traveled from there, visiting Holocaust sites in Europe before going to Russia and China.

He entered China with a valid visa and renewed it twice, his father said.

Paul Solondz said that evidence at the trial in China suggested that his son had used chemicals to press the marijuana leaves into a liquid, but the result was an unusable, toxic mixture. Justin did not want to dispose of the liquid for fear of damaging the environment, but after his arrest, a friend tried to do Justin a favor by burying the leaves in the courtyard.

Paul Solondz and Justin’s mother, Bianca Franchi, traveled to China last month and were allowed to see him for an hour. Solondz said his son seemed unclear on the nature of the U.S. charges and also did not know that his ex-girlfriend, Briana Waters, had been sentenced to six years in prison for her role as a lookout in the university fire.

Solondz said he was “repulsed” that environmentalists are labeled as terrorists, adding: “No one has been injured. No animal has been hurt. The only credo I ever saw from this group was that they were not to hurt or maim or kill any people or animals.”

Prosecutors in the United States say that Justin was involved in arsons at the Litchfield Wild Horse and Burro Corral in Susanville, Calif., and at a Monsanto Corp. canola field in Dusty, Wash. He was charged with girdling about 800 hybrid poplar trees on Oregon State University property, and with making incendiary devices used to destroy several buildings at a poplar farm in Clatskanie, Ore., the same night as the university fire.