I wouldn't be surprised. Read up about the case of Katrina Leung https://www.theguardian.com/world/2003/apr/22/china.usa

Born in China but an American citizen, she had helped the former LA mayor, Richard Riordan, in his unsuccessful attempt to win the Republican party's nomination for last year's California gubernatorial race.

Since the 80s, however, Ms Leung had had another source of income. She had received around $1.8m (£1.2m) by working undercover as an FBI "asset". Travelling between LA and China, she had been in regular contact with Chinese officials and had been feeding back information to her two FBI handlers, James J Smith and William Cleveland.

What the FBI hierarchy was unaware of, however, was that she and Mr Smith had become lovers shortly after she started working and that their affair had continued beyond the latter's retirement in 2000. According to the FBI, she would take documents from Mr Smith's briefcase, photocopy what she wanted and pass the information to the Chinese.

Ms Leung had also reportedly become the lover of her other handler, Mr Cleveland, who was based in San Francisco, and their relationship was to lead to her slow but eventual downfall.

Listening in to some intercepts in the early 90s, Mr Cleveland recognised her voice and alerted her chief handler, Mr Smith, who promised to investigate. But it was not until after Mr Smith had retired that other agents started to investigate her and traced back the warning signs. She and Mr Smith were taped having sex in a hotel and the pair of them were confronted by the FBI.