BEIJING — A Chinese dissident who campaigned for the parents of children killed in last year's Sichuan earthquake was sentenced Monday to three years in jail on a state secrets charge, his wife said.

Huang Qi, 46, who had investigated accusations that shoddy school construction contributed to the quake's heavy toll, was found guilty by a court in the city of Chengdu of possessing state secrets, his wife Zeng Li told AFP.

"We will surely appeal," she said by phone from Chengdu, the capital of Sichuan province.

The sentence came just days after US President Barack Obama paid his first visit to China, during which he raised the issue of human rights, saying the United States believed in fundamental rights for all people.

US ambassador Jon Huntsman also specifically brought up Huang's case with the Chinese government in the lead-up to Obama's visit, a US embassy official told AFP.

The sentencing was the second move since Obama's visit by Chinese authorities against dissidents.

On Thursday, Zhou Yongjun, a student leader of China's 1989 Tiananmen Square protests, was tried for fraud, also in Sichuan.

No verdict has been announced in Zhou's case.

The nature of the state secrets in Huang's case was not publicly released, but his lawyer Mo Shaoping denounced the verdict, saying it was information freely available on the Internet, although he declined comment on it.

"We do not acknowledge the verdict. We maintain that he is innocent," Mo said.

Calls to the court, in Chengdu's Wuhou district, went unanswered.

The London-based rights group Amnesty International demanded Huang's immediate release and condemned the use of "vague" state secret laws to silence dissent.

"He should never have been detained in the first place and should be released immediately," Sam Zarifi, Amnesty's Asia Pacific director, said in a statement.

"These laws are used extensively to retroactively penalise lawful human rights activities and restrict freedom of expression."

Amnesty further expressed concern for Huang's "deteriorating health" and allegations of mistreatment while in police custody.

Huang was taken into custody in June 2008, weeks after the 8.0-magnitude quake struck on May 12, leaving nearly 87,000 dead or missing.

The government has said the toll included 5,335 children killed in school collapses.

The high student toll prompted accusations that official corruption left many schools poorly constructed, causing them to collapse while many other adjacent structures withstood the quake.

China Human Rights Defenders, a network of domestic and overseas activists, said it was believed Huang was imprisoned for reporting on the issue and giving interviews to foreign journalists about it.

Earlier this month the US Congress unanimously approved a resolution expressing "support" for Huang and detained activist Tan Zuoren -- who was also working on the school issue -- and called for them to receive fair trials.

Huang was previously jailed from 2000 to 2005 for "inciting subversion."