WASHINGTON — (CNN) Caroline Kennedy, the U.S. ambassador to Japan, used a personal email to conduct official business — as former Secretary of State Hillary Clinton did — according to a new State Department report.

Many State Department staff used their private accounts to both send and receive these emails, the State Department’s inspector general found in an investigation of Kennedy’s embassy in Tokyo.

“Senior embassy staff, including the ambassador, used personal email accounts to send and receive messages containing official business,” investigators wrote in the report, released Tuesday. “In addition, (investigators) identified instances where emails labeled sensitive but unclassified were sent from, or received by, personal email accounts.”

The watchdog report said that Kennedy’s practices were against State Department policy and put the agency at risk.

Clinton, who served as secretary of state during President Barack Obama’s first term, has had her campaign’s opening months dogged by investigations for similar private email use.

Republicans have charged Clinton violated the law, but her campaign maintains that Clinton has done nothing wrong.

Kennedy, the daughter of president John F. Kennedy, has returned to the spotlight since Republican presidential front-runner Donald Trump began questioning her qualifications for the diplomatic job, which he claims she got due to a favor from the White House.

“I mean, she’s a very nice person, my daughter likes her … Caroline Kennedy. OK, in Japan. She didn’t even know how she got the job,” Trump told CNN’s Chris Cuomo in an interview last week.

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