Liang Daoxing, former deputy mayor of Shenzhen, is under investigation on suspicion of a serious disciplinary violation, making him the fifth high-level official caught up in anti-graft efforts in Guangdong province in just over a month.

The investigation into Liang was announced on the website of the Guangdong Provincial Party Commission for Discipline Inspection on Saturday.

Liang, 63, was deputy mayor of Shenzhen between 2002 and 2009. He acted as director-general of the executive office of the 26th Summer Universiade, which the city hosted in 2011.

Anti-graft measures have affected a number of Guangdong officials in recent weeks, including Wei Jinfeng, former deputy director of the provincial finance department, who was expelled from the Party and public office on Oct 25. He was found to have accepted bribes and financially benefited from illegal land transactions.

Lu Yingming, former deputy director of the provincial land and resources department, Zheng Beiquan, former deputy mayor of Yingde, and Chen Hongping, former Party chief of Jieyang, are also the subject of investigations, according to the local discipline watchdog.

Zheng, who was also former head of the public security bureau of Yingde, is being investigated on suspicion of bending the law for selfish ends and serious economic issues.

Zheng's case first made headlines after a deputy director of the public security bureau of Yingde reported Zheng's connections to gangsters to government departments in September. It was said that Zheng was acting as the "protective umbrella" for a local drug gang.

The number of cases indicates a strengthened crackdown on corruption, which has become an important issue for the central leadership after the 18th National Congress of the Communist Party of China, said Zhang Jingen, a professor with the center for anti-corruption studies at the Sun Yat-sen University in Guangzhou.

During a group study of the newly elected political bureau of the CPC Central Committee on Nov 17, Xi Jinping, general secretary of the CPC Central Committee, urged senior officials to root out corruption and asked them to prevent their relatives and intimates from abusing their influence for personal gain.

It was the second time in a week that Xi had spoken about anti-graft since being elected leader of the CPC.

The five cases in Guangdong reflect the seriousness of anti-graft efforts in the province, Zhang said, adding that such efforts should primarily be aimed at high-ranking officials as their actions are more serious and have a greater effect on society.

liwenfang@chinadaily.com.cn