The employee told the New York Times young Bo Guagua, 24, a student at Harvard, was listed by the government as one of the official reasons for his father's fall from power.
Bo Xilai faces charges of corruption and abuse of power while his wife Gu Kailai is accused of killing British businessman Neil Heywood who reportedly helped the younger Bo obtain a spot at the elite Harrow School in London.
In England, Bo Guagua developed a reputation as an academically indifferent bon vivant.
His exploits have become a staple of social-media gossip in recent years.
"If you're discreet, they look the other way," the former government employee said. "But Guagua's behavior was striking by the standards; urinating against a fence at Oxford, kissing foreign girls -- it all goes down bad in China."
Bo Guagua is unlikely to return to China anytime soon given the ongoing corruption investigation involving his father.