Donald Trump’s daughter has been formally asked to co-operate with an investigation onto the deadly Capitol Hill riots and will be questioned in particular about a key phone call she overhead while in the inner circle.

The US House of Representatives’ panel investigating the January 6, 2021 attack has formally sought an interview with Ivanka Trump who was a senior White House advisor.

In a letter to Ms Trump, lawmakers requested her voluntary co-operation and said they would limit questions to issues surrounding that day, including activities leading up to or influencing it and her role in the White House at that time.

The panel noted that Ms Trump “was present in the Oval Office” during key conversations leading up to January 6 and observed a telephone conversation between her father and then vice-president Mike Pence on the morning of the riots.

The panel said Ms Trump was privy to the former US president’s side of the conversation, in which he tried to convince Mr Pence to impede the certification of the 2020 presidential election.

The panel is asking Ms Trump for her recollection of that conversation and any others she may have heard where Mr Trump tried to halt the election certification process.

The former president has criticised the committee’s probe as a partisan effort, and has sought to block other aides’ testimony and White House documents from reaching the panel.

Ivanka Trump and husband Jared Kushner in life after the White House. Photo: Getty

A lawyer for Ms Trump could not be immediately reached to comment on the committee’s request.

US Representative Liz Cheney, vice chair of the committee and one of its two Republican members, said earlier this month that the panel had “first-hand testimony” that Ms Trump asked her father to intervene during the Capitol riots.

“We know his daughter – we have first-hand testimony that his daughter Ivanka went in at least twice to ask him to ‘please stop this violence,'” Ms Cheney said in a January 2 interview with ABC News.

-with AAP