BEIJING- A Chinese activist who was investigating whether shoddy construction caused school collapses in the massive 2008 Sichuan earthquake was jailed Tuesday for five years for subversion, his lawyer said.

Environmental activist and writer Tan Zuoren was convicted of "inciting subversion of state power" over his criticisms of China's handling of the Tiananmen crackdown in 1989, said one of his lawyers, Pu Zhiqiang.

But Tan was arrested last year as he was probing the deaths of thousands of children when their schools collapsed in the May 2008 quake in the southwestern province of Sichuan, which left nearly 88,000 people dead or missing.

Rights watchdog Amnesty International has said, citing local sources, that Tan's independent investigation was likely the real reason for his detention.

"He was sentenced to five years in prison for inciting subversion of state power and deprived of his political rights for three years," said the lawyer, Pu.

"There were no charges related to the quake. All of the proceedings were linked to June 4 (1989)," Pu told AFP by telephone.

The lawyer said the verdict from the court in the Sichuan provincial capital Chengdu was read out in less than 10 minutes.

Court officials were not immediately available for comment.

Schools bore the brunt of the Sichuan quake, with thousands collapsing on top of students, fuelling angry charges from parents that corruption had led to shoddy construction.