US President Donald Trump’s daughter Ivanka Trump used a personal email account last year to send hundreds of emails to White House aides, Cabinet officials and assistants, according to emails released by a nonpartisan watchdog group.

Many of the emails from the White House senior adviser were “in violation of federal records rules”, reported The Washington Post, which broke the potentially explosive story on Monday (US time).

The exclusive claimed that White House ethics officials uncovered Ivanka’s repeated use last year of personal email during an investigation sparked by a public records request from watchdog group American Oversight.

“The President’s family is not above the law, and there are serious questions that Congress should immediately investigate,” Austin Evers, the executive director of American Oversight, said.

“Did Ivanka Trump turn over all of her emails for preservation as required by law? Was she sending classified information over a private system?”

The Presidential Records Act requires all official White House communications and records be preserved.

The first daughter in the Roosevelt Room on September 17. Photo: Getty

A central part of Mr Trump’s campaign against Hillary Clinton in 2016 was that she used a private email server instead of a government email account during her time as secretary of state.

Mr Trump labelled her “crooked Hillary” and his supporters often chanted “lock her up!” at the mention of Mrs Clinton.

The former first lady was not charged with bending the Presidential Records Act, which has led Mr Trump to frequently claim she received special treatment.

Ivanka’s personal account was used to discuss official business and government policies less than 100 times, sources familiar with the White House review told The Post.

But records law might also have been violated by hundreds of messages related to her official work schedule and travel details she sent herself and staff who cared for her children and home.

Ivanka with Jared Kushner and sons Theodore (left) and Joseph on July 29. Photo: Getty

Some White House aides were “startled” by the number of Ivanka’s personal emails, and “taken aback by her response when questioned about the practice”, reported The Post.

Its report said the mother of three claimed she was not “familiar” with some details of the rules, according to insiders.

The White House referred requests for comment to Ivanka’s lawyer and ethics counsel Abbe Lowell.

The first daughter used her private email before she was briefed on the rules, but none of her messages contained classified information, acknowledged a spokesman for Mr Lowell, Peter Mirijanian.

“Like most people, before entering into government service, Ms Trump used a private email,” Mr Mirijanian said.

He said while “transitioning” into government, “Ms Trump sometimes used her private account, almost always for logistics and scheduling concerning her family”.

American Oversight’s Mr Evers said that for “more than two years” Mr Trump and senior Congress leaders had viewed the use of personal email servers for government business to be serious enough to warrant prosecution.

“We expect the same standard will be applied in this case,” he said, calling out the “obvious hypocrisy” that Ivanka’s father had misuse of personal email as a central campaign plank.

“There is no reasonable suggestion that she didn’t know better. Clearly everyone joining the Trump administration should have been on high alert about personal email use.”