The rift between China’s two most important financial regulators is not especially rare but it matters more now because of fears the country could face its “Lehman moment”.

In fact, it is partly fear of a financial crisis, particularly in the huge “shadow banking” sector, that has caused relations between the China Banking Regulatory Commission and the People’s Bank of China, the central bank, to become so poisonous.

Several people familiar with the matter said relations between the two bodies turned especially nasty in June, when the central bank allowed liquidity to dry up in the interbank market. That sent short-term interest rates soaring and confronted investors with the prospect of a Chinese financial crisis for the first time in a decade.