A former CIA operative has been arrested after investigators suspected he secretly helped bring down America’s network of informants in China.

Jerry Chun Shing Lee, a 53-year-old US citizen, was intercepted after he arrived at John F. Kennedy airport in New York in the climax of a six-year investigation.

He was charged with unlawful retention of national defence information after being previously found with two notebooks containing classified material.

The handwritten notes reportedly included the real names and phone numbers of undercover officers as well as the addresses of covert facilities and operational notes.

The books were discovered in 2012 but Mr Lee left the country for Hong Kong in 2013. It is unclear why he decided to return to America this week.

The arrest, first reported by The New York Times, marks a major development in an investigation into one of America’s biggest intelligence failures in decades.