Authorities alleged that American pro-democracy activist detained more than a month ago in Vietnam was suspected of plotting an attack on a U.S. Consulate, state-controlled media reported Wednesday.

Cong Thanh Do, 47, of San Jose, Calif., was arrested on Aug. 14 while on vacation in south central city of Phan Thiet, his family has said.

"Vietnamese security agency, through documents and evidence, determined that Cong Thanh Do's job on the trip to Vietnam this time was to carry out terrorist plots, including suspected plot to target U.S. Consulate in Ho Chi Minh City," the Communist Party newspaper Nhan Dan (People) quoted a police report as saying.

The newspaper said representatives from the Ministry of Public Security's Anti-terrorist Department have met with a U.S. Consulate representative and provided him with the documents and evidence of Do's lawbreaking activities.

U.S. embassy spokesman Lou Lantner confirmed the meeting, but declined to give further details.

U.S. ambassador to Vietnam Michael Marine said earlier this month that he had seen no evidence that Do was plotting an attack against a U.S. target in the country.