Corruption is the biggest threat to China's Communist Party, President Xi Jinping said on Monday, in a clear warning that the ruling party is resolved to tackle a long-running problem that is now entrenched in many strata of Chinese society.

More than 200 specialized detention facilities have been built or expanded across China, a CNN investigation finds, as the Chinese leader extends his crackdown beyond the ruling Communist Party to a vast swath of public sectors.

Even the lowly 'flies' and 'ants' in China's vast bureaucracy will not be spared in the corruption fight, a state broadcaster television program showed Sunday.