An internal Communist Party investigation found Qin to have had an extramarital affair during his tenure as Beijing’s top envoy to Washington. 

Qin, once considered a trusted aide to Xi Jinping, was stripped of his title in July, after he disappeared from public view a month earlier. 

The officials were further told that the probe found Qin's extramarital affair even led to the birth of a child in the US, as per the Wall Street Journal.

Source: Crux - YouTube