BEIJING (AFP) - A top official at Chinas food and drug safety watchdog who is under investigation has been linked to alleged bribery cases involving US giant Johnson & Johnson, a Chinese newspaper reported. Zhang Jingli, one of four deputy heads of Chinas State Food and Drug Administration (SFDA), is being investigated for suspected serious disciplinary violations, the official Xinhua news agency reported earlier this week. The report gave no further details, but respected weekly the Economic Observer said Zhang was outed when authorities started probing drug firms including the Shanghai branch of Johnson & Johnson for alleged bribery. He was investigated on May 27, the report quoted an unnamed source at the SFDA as saying. The source added that the main reason for the probe lay in Shanghai-based Johnson & Johnson Medical, according to the report, which was published Friday. No further details were given about the alleged bribery investigations, other than they involved medical equipment. Citing several other unnamed sources, the report said six other officials at the SFDA were also being investigated in relation to the cases. Zhang, who has been sacked, took up his post in 2003 and remained immune to a huge shake-up in the organisation after former SFDA head Zheng Xiaoyu was executed for accepting bribes, the report added. Johnson & Johnson Medical in Shanghai were unavailable for comment on Saturday, as were the groups headquarters in the United States and the SFDA. Corruption is widespread in China, and the nations top leaders have repeatedly warned that it threatens the Communist Partys ability to rule.