Zhou Yongkang, China's ex-security chief who is under investigation on allegations of seriously violating Party political, organizational and confidentiality discipline, once formed a clique with Bo Xilai, the former Party chief of Chongqing who was sentenced to life imprisonment for corruption, according to a report by Phoenix Weekly, a magazine run by Hong Kong broadcaster Phoenix Television.

An article in the latest edition of the magazine said Zhou and Bo, both former members of the Political Bureau of the Central Committee of the Communist Party of China, the top Chinese leadership body, had an off-the-record talk in Chongqing.

During the talk, the article said, Zhou and Bo agreed that a theory proposed by Chairman Mao Zedong that the contradiction between the proletariat and the bourgeoisie is the principal contradiction in Chinese society is correct and that the policy of reform and opening-up, proposed by the former top leader Deng Xiaoping, should be adjusted.

The pair celebrated their political rapport and said they would "play a big game", the article said. The report did not attribute the reported conversation to anyone or provide any official confirmation.

Given that China's reform and opening-up was decided at the Third Plenary Session of the 11th Communist Party of China Central Committee in 1978, Zhou and Bo's objections to the policy cannot be tolerated by the Party, the article said.

It added that Zhou did not report his talk with Bo to the Central Committee but told close associates that Bo could help him "charge forward".

The article said Zhou, as the former security chief, had access to top-secret information about the country and the Party.

Zhou's alleged violation of confidentiality may suggest he gave his accomplices advance information on personnel arrangements that would be announced during the 18th CPC National Congress and leaked economic secrets to others for huge profits, the article said.

It also alleged Zhou informed Bo when Wang Lijun, Chongqing's former deputy mayor and ex-police chief, entered the US consulate in Chengdu in an attempt to defect in 2012.