BEIJING, Sept. 28 -- A local public security official is under investigation following a jailbreak in northeast China's Heilongjiang Province earlier this month, according to the Supreme People's Procuratorate (SPP) on Sunday.

Deputy head of the Yanshou county public security bureau Zhang Xiuli is investigated for dereliction of duty, it said.

A total of four police officers have been suspended after three inmates escaped a detention center and killed a guard in Yanshou county on Sept. 2.

The officers included head, deputy head and a police officer from the detention center as well as Zhang Xiuli, who was in charge of the detention affairs.

The three fugitives at large have all been captured after over 1,000 police officers were put onto the search.

The malpracticed police officers will be dealt in line with the law, said the SPP.