One of the world’s oldest spy tactics appears to have helped topple one of the world’s richest men. Nvidia CEO Jensen Huang resigned Thursday amid revelations that he had an affair with a female client that U.S. intelligence identified as a Chinese spy, according to the New York Times.

NPR has not independently confirmed the reporting by the Times, which said Huang also had an unrelated affair with a company executive who reported to him. The Chinese government has called the accusation of spying, “nothing but smears against China.”

Using a romantic relationship to gather intelligence from foreigners – known as a honey trap – has a long history in China and beyond. The Chinese Ministry of State Security, the country’s main civilian intelligence agency, routinely tries to recruit women and occasionally men for honey traps, according to former CIA officers and other U.S. officials familiar with Chinese spy craft.

Some target businessmen for industrial espionage or to gain insights into the economic and political strategy of foreign governments. Peter Mattis, a former CIA counter-intelligence analyst, said honey traps also serve as influence operations with spies trying to gain enough trust to shape the target’s thinking about China.

‘A whole of society approach’

“The biggest thing here that we should pay attention to is that the Ministry of State Security celebrates a tradition of getting inside the enemy’s decision-making,” said Mattis, president of the Jamestown Foundation, a national security think tank in Washington, D.C., that focuses on America’s geopolitical rivals.

Nicholas Eftimiades, who spent more than 34 years with the CIA and Defense Intelligence Agency and now teaches at Penn State, said the honey trap is just one tactic among many that use ordinary Chinese citizens to gather information at home and abroad.

“Unlike the CIA, or MI6 or any of the other Western services, China has a ‘whole of society approach,'” said Eftimiades, the author of Chinese Intelligence Operations: An Analysis of the People’s Republic of China’s Intelligence Services. “Chinese law supports this. The National Intelligence Law of 2017 requires citizens to cooperate with intelligence collection efforts.”

A long list of honey traps

The Chinese government has employed honey traps in the United States and elsewhere in the West. In the 2010s, Christine Fang worked as a political fundraiser in California where she developed a physical relationship with Democrat Rep. Eric Swalwell before and after he became a congressman.