HANOI, Vietnam -- Vietnam on Thursday deported a Silicon Valley engineer who had been imprisoned for allegedly plotting against the communist government.

Vietnamese-born Cong Thanh Do, 47, was arrested Aug. 14 while on vacation in the south-central city of Phan Thiet, his family has said.

State-run Vietnam Television broadcast pictures Thursday of Cong Thanh Do checking in at Ho Chi Minh City airport.

Do's daughter, Bien Dobui, later confirmed that report, saying her family had talked to Do while he was at the airport in Taipei, en route to his home in San Jose. They expected him to arrive in San Francisco later Thursday, she said.

"I'm really happy," she said in a telephone interview. "He talked to my mom on his cell phone, and they were both very emotional."

Police arrested Vietnamese-born Do on Aug. 14 while he was on vacation in the south-central city of Phan Thiet, along with two Vietnamese citizens.

Police accused them all of setting up the anti-government People's Democracy Party, and printing and disseminating pamphlets in Ho Chi Minh City and some other provinces calling for an end to the Communist Party's monopoly on power.

Do's family denies all the accusations, saying he had simply returned to his homeland as a tourist.

Earlier this week, the Communist Party newspaper Nhan Dan (The People) quoted a police report as saying that Do was suspected of plotting to attack the U.S. Consulate in Ho Chi Minh City.

He was held for more than a month without charges being filed against him.

Neither Vietnamese police nor U.S. Embassy officials were available for comment Thursday.

U.S. Ambassador Michael Marine said earlier this month that he had seen no evidence that Do was plotting an attack.

Do, an engineer, immigrated to the United States in 1982 and has returned to Vietnam several times since, his family has said.