Top White House aides emailed Hillary Clinton on at least one of several private email accounts during her first year in office, suggesting President Obama's staff knew about the secretary's controversial email arrangement as early as 2009.

Clinton's chief of staff, Cheryl Mills, passed Clinton's private email address to David Axelrod, then a senior Obama adviser, in June 2009.

Weeks later, Axelrod sent a note of sympathy to the secretary after learning she had fallen and hurt herself.

Mills ensured Clinton was comfortable sharing her private email address again in September 2009 before giving it to Rahm Emmanuel, Obama's chief of staff.

White House Press Secretary Josh Earnest has said he doesn't know whether Obama's staff was aware of Clinton's private email use.

Lawyers for the White House told the Associated Press in March the counsel's office had no idea Clinton had constructed her own server while in office.

The revelations that senior Obama staff had emailed Clinton on her private address long before use of the account was publically known emerged Tuesday in a batch of roughly 1,900 emails released by the State Department in compliance with a court order.