Ivanka Trump used a personal email account to communicate with a government official after her father became president, documents obtained by the nonprofit American Oversight have revealed.

The documents, obtained through the Freedom of Information Act (FOIA) shared exclusively with Newsweek (IBTimes.co.uk's sister publication), show the president's daughter used a personal email address to contact Small Business Administration (SBA) Administrator Linda McMahon in February.

Ivanka wrote she wanted to "explore opportunities to collaborate" with the department on "women's entrepreneurship".

"Dina [Powell, the White House deputy national security director] and I are very excited about your focus on women's entrepreneurship and would love to assist you in any way we can," she told McMahon.

The Hill noted that the email exchange with McMahon happened about a month before Ivanka became an official government employee.

However, she had already been involved with high-level meetings within the administration, Newsweek reported.

Ivanka copied her chief of staff, Julie Radford, and Powell on the emails. Radford has a White House email account, the Hill reported.

"Ivanka Trump was not a federal employee in February. She elected to become a federal employee in March. At the time she did so, she made clear that one of her reasons for doing so was to ensure that she would have access to government-issued communications devices and receive an official email account to protect government records," a White House spokesman said.

The spokesman continued: "Prior to obtaining an official account, Ivanka's communication to Administrator McMahon's official account ensured the records were preserved and available under the Federal Records Act."

The news comes a day after it was revealed that her husband, senior adviser Jared Kushner, also used a personal email address to conduct official government business.

Politico reported that Kushner had communicated with administration officials through an email account set up during the transition period. He reportedly exchanged at least two dozen emails that way. There is no evidence that the emails contained classified or sensitive information.

"Yet again we see that there's one rule for the Trump family and another for everyone else," Austin Evers, the executive director of American Oversight and a former senior counsel at the Department of State, said to Newsweek.

"It's simply breathtaking that both Ivanka and Jared Kushner would conduct government [work] on a personal email account after running a campaign centred on that very issue," Evers said, referring to the campaign against Hillary Clinton's use of a personal email server.

"The fact that they would brazenly ignore rules governing email use raises even more questions about their judgement and fitness to hold positions in the White House."

Newsweek noted that now that Ivanka Trump is an official employee at the White House, her communications are not subject to FOIA requests.