China has failed to curb excesses in its credit system and faces mounting risks of a full-blown banking crisis, according to early warning indicators released by the world’s top financial watchdog.

A key gauge of credit vulnerability is now three times over the danger threshold and has continued to deteriorate, despite pledges by Chinese premier Li Keqiang to wean the economy off debt-driven growth before it is too late.

The Bank for International Settlements warned in its quarterly report that China’s "credit to GDP gap" has reached 30.1, the highest to date and in a different league altogether from any other major country tracked by the institution. It is also significantly higher than the scores in East Asia's speculative boom on 1997 or in the US subprime bubble before the Lehman crisis.

Studies of earlier banking crises around the world over the last sixty years suggest that any score above ten requires careful monitoring. The credit to GDP gap measures deviations from normal patterns within any one country and therefore strips out cultural differences.

It is based on work the US economist Hyman Minsky and has proved to be the best single gauge of banking risk, although the final denouement can often take longer than assumed. Indicators for what would happen to debt service costs if interest rates rose 250 basis points are also well over the safety line.