More than three-quarters of the mainland's banking scandals are caused by finance officials abusing their positions, according to the chairman of China's banking watchdog. China Banking Regulatory Commission chairman Liu Mingkang made the remarks during a speech at Tianjin's Nankai University on Saturday to mark his appointment as a part-time economics professor, mainland media reported yesterday. Mr Liu said recent banking scandals had shown that the main problem with Chinese banks was that branch directors were too loosely supervised and operated in an environment of abnormal corporate credit and weak internal management. Mr Liu described criminal activities in China's finance sector as the 'three 80 per cent phenomena', meaning bank officials were involved in 80 per cent of all scandals, 80 per cent of cases occurred within local branches, and collusion between bank insiders and outsiders was seen in 80 per cent of the crimes. Several large banking scandals involving local bank heads have emerged on the mainland in the past few years. One of the most recent was a series of fraud cases at four state banks in Shanxi province that led to the loss of more than 1 billion yuan in bank deposits. Another billion-yuan fraud was allegedly planned by Gao Shan , a director of a Bank of China division in Harbin , capital of Heilongjiang province . Mr Gao fled overseas earlier this year after allegedly transferring about 1 billion yuan to foreign bank accounts.