Two senior prison officers are being investigated for allegedly aiding an inmate who seduced three women through cell phone conversations and extorted more than 110,000 yuan ($17,700) from two of them.

The flaws in the country's prison management have been in the headlines in the wake of reports detailing the allegations of jailhouse sex between a woman and a 28-year-old inmate in Nehe prison in Nehe, Heilongjiang province.

The head of the prison, Wang Meng, and his deputy, Zhu Dengtao, have been held for investigation on charges of dereliction of duty, China's top procuratorate announced on Tuesday.