HANOI (Reuters) - Vietnamese police detained a French dissident of Vietnamese descent for deportation on Friday after the Communist state revoked his Vietnamese citizenship last month, his wife said.

Pham Minh Hoang, a 61-year-old activist and mathematics lecturer, had dual French and Vietnamese citizenship before Vietnam canceled his citizenship without giving a reason, a move that drew criticism from human rights groups.

Despite sweeping reforms to the economy and growing openness to social change, the Communist Party retains tight media censorship and tolerates no criticism. Dozens of bloggers and activists are serving sentences for crimes against the state.

Hoang’s wife, Le Thi Kieu Oanh, said police came to their house in Ho Chi Minh city on Friday asking to carry out a regular check on their household registration but later forced Hoang to leave with them and said they would deport him the next day.

“My husband refused to go but three to four police officers used violence to drag him out and locked me inside the house... They also parked a signal-jammer car right in front of our house,” Oanh said.

The French embassy in Vietnam said France regretted the Vietnamese authorities decision to revoke Hoang’s Vietnamese nationality and to deport him.

“Freedom of expression and of opinion, notably on the Internet, are both guaranteed by the international covenant on civil and political rights to which Vietnam is a party. France calls on Vietnamese authorities to ensure compliance with these commitments”, the embassy said in a statement sent to Reuters.

Ho Chi Minh police said they could not provide any information on the case.

Hoang was sentenced to three years in jail for attempted subversion in 2011 but was released after 17 months and served three years under house arrest. He frequently posts blogs criticizing the Vietnamese government.

Oanh said the couple were informed on June 1 by the French consul-general that Hoang’s Vietnamese citizenship was being annulled with a month for him to leave the country, but they refused to comply. “It’s Hoang’s ideal to stay in Vietnam to raise a voice and contribute to building freedom and democracy,” Oanh said.

“After the signal-jammer car left I called the consul general and he just said he acknowledged the situation. What they would do after that, I don’t know,” she added.

She said the French embassy and consulate in Vietnam were waiting for guidance from the French foreign ministry because Hoang’s Vietnamese and French passports have expired.

Vietnam’s foreign ministry spokeswoman Le Thi Thu Hang last week defended the decision to revoke Hoang’s citizenship, saying it was “conducted in accordance with the provisions of Vietnamese law.”

Hoang is a member of California-based Viet Tan, a group Vietnam considers a terrorist organization.

“The French government should not take part in the Hanoi regime’s brazen exile of a well-known human rights activist,” Viet Tan said in a statement.