US congressional investigators have asked Ivanka Trump, the daughter of the former president, to testify about the January 6 riot at the US Capitol, BBC reported.
The move to request testimony from a Trump family member marks an escalation of the committee's probe of the riot.
A mob stormed the Capitol as lawmakers met to confirm President Biden's win.
Ivanka Trump, Donald Trump's eldest daughter, served as one of his senior advisers during his presidency, alongside her husband Jared Kushner.
The committee says she participated in efforts to convince Trump to call off his supporters during the violence.
The representative did not say whether she would comply with the voluntary request.
The panel is also seeking the phone records of Trump's son Eric Trump, as well as Kimberly Guilfoyle, who is engaged to Mr Trump's other son, Donald Trump Jr.