GUANGZHOU - Police in South China's Dongguan city are looking into the case of the Beijing airport bomber, allegedly beaten by security officers.

The public security bureau of Dongguan, in Guangdong province, confirmed on Monday that it had filed a criminal investigation of the "intentional injury" of Ji Zhongxing.

Ji was sentenced to six years in prison last week for setting off a home-made explosive device at Beijing Capital International Airport in July, severely injuring himself.

Ji once worked in Guangdong and claimed that he was beaten in 2005 by local public security officers, resulting in his paralysis.

Dongguan police said further investigation into Ji's alleged beating is under way.