Updated

A North Korean woman accused of using "sex as a tool for her spy activity" and plotting to assassinate South Korean intelligence agents with poisoned needles has been arrested, prosecutors said Wednesday.

The suspect, identified as Won Jeong-hwa, 34, confessed after her July 15 arrest that she was a spy trained and commissioned by North Korea's intelligence agency, prosecutors said in a statement.

She is the first alleged North Korean spy arrested in South Korea since 2006, and the second in a decade, the statement said.

No trial date has been set for Won, who was arrested on charges of spying and is in custody. If convicted, she faces anywhere from seven years in prison to execution.

Won entered the South in 2001 after marrying a South Korean businessman in China, falsely reporting to authorities that she was a defector from the communist North, prosecutors said. She and her husband immediately divorced.

While in the South she gathered and passed classified information on to the North, including the locations of key military installations, lists of North Korean defectors and personal information on South Korean military officers, the statement said.

She dated a South Korean army captain and the officer cooperated with her, providing a list of North Korean defectors and destroying her faxed reports to the North's spy agency. The captain, identified only by his surname Hwang, also was arrested, the statement said.

The statement said Won often traveled to China to visit the Chinese office of the North's spy agency, where she received instructions and money for her mission. Prosecutors said she received a total of $60,000 worth of cash and goods from the office.

The two Koreas fought the 1950-53 Korean War that ended in a truce, not a peace treaty, which means the peninsula still remains technically at war.

Their relations had warmed significantly after the first-ever summit of their leaders in 2000, but chilled again this year after conservative South Korean President Lee Myung-bak took office in February with a pledge to get tough on the North.