WASHINGTON — While American intelligence authorities investigated a possible C.I.A. mole in recent years, they discovered that one former agency officer had received hundreds of thousands of dollars in unexplained bank deposits, current and former government officials said on Wednesday.

The money deepens the mystery surrounding Jerry Chun Shing Lee, the former C.I.A. officer, who faces a charge of keeping national security secrets in his notebooks after he left government. It helps explain why many American law enforcement officials suspected that Mr. Lee had provided information to China — a suspicion for which no direct evidence has surfaced.

The F.B.I. arrested Mr. Lee this month in New York after a lengthy counterintelligence investigation that began several years ago when the C.I.A.’s informant network in China was compromised and many of its assets were imprisoned or killed. It was a devastating blow to the C.I.A.’s ability to collect intelligence in China and is regarded inside the government as one of the worst compromises in modern American intelligence.

Mr. Lee, 53, is awaiting transfer to federal court in Northern Virginia, where he was charged. His family has declined to comment, and no lawyer has appeared on his behalf. A Justice Department spokesman declined to comment.