WASHINGTON: The FBI opened a counterintelligence investigation of a veteran US diplomat after intercepting the communication of a Pakistani official that indicated the woman might have been involved in providing secrets to the Pakistani government, US officials said.

The intercept triggered months-long surveillance of Robin Raphel, a former ambassador and assistant secretary of state, and eventually led the bureau to obtain a warrant to search her home in Washington; her office at the State Department was also searched. It is unclear what form of communication was intercepted by the United States.

One US official, speaking on the condition of anonymity to discuss an ongoing case, said the bureau found classified information at Raphel’s home.

The New York Times first reported on the intercept and the lengthy surveillance of Raphel, 67, who has not spoke publicly since news of the investigation broke this month.

“Ambassador Raphel is a highly respected career diplomat who has dedicated her life to serving the United States and its interests,” said Amy Jeffress, Raphel’s attorney and the former chief of the National Security Section in the US Attorney’s Office for the District of Columbia.