Chelsea Clinton worried during her mother's tenure at the State Department that the Clinton Foundation could lose its tax-exempt status if it continued to let its employees engage in conflicts of interest.

Her fears were revealed in an email made public Monday by WikiLeaks, which has to date published more than 30,000 emails obtained illegally from the inbox of John Podesta, Hillary Clinton's campaign chair.

In the Dec. 2011 email, Chelsea Clinton told Cheryl Mills that the charity's structure needed an overhaul in the interest of "protecting my father and the non-profit status of the foundation." Mills was Clinton's chief of staff at the State Department when Clinton wrote the email, and she's now a board member at the foundation.

At the time, Chelsea Clinton and a top aide to Bill Clinton, Doug Band, were sparring over the many conflicts of interest that he and other senior staffers had created by blurring the lines between their personal and philanthropic affairs.

Bill Clinton was cited as one of the worst offenders. Band complained to Podesta that the former president accepted personal paychecks from three separate Clinton Global Initiative donors and took home "expensive gifts" from other contributors.

In the conversation between Mills and Chelsea Clinton, Mills said Bill Clinton spent "more than half of his allocated time" on "political, for-profit, personal" activities as one reason the foundation needed to address "overlapping accountabilities."

The Clinton Foundation has been criticized for enabling conflicts of interest while Hillary Clinton served as secretary of state. Mills was coaching Chelsea Clinton on how to approach the organization's restructuring, and Huma Abedin, then Hillary Clinton's deputy chief of staff, obtained a rare personnel waiver that allowed her to work for both the State Department and the Clinton Foundation — as well as Band's consulting firm, Teneo Strategies — during the final year of Hillary Clinton's tenure.

Band left the foundation in an official capacity in 2011 to co-found Teneo but continued to advise the charity, other emails released by WikiLeaks show. Bill Clinton collected a generous paycheck from Teneo at the same time while serving as an adviser to the consulting firm.