Some of US President Donald Trump’s closest advisers, including his daughter Ivanka, were missing from a list of people that Democratic lawmakers sought documents from on Monday for a corruption investigation of the president.

The list covered a who’s who of Trump family members and associates, but Ivanka Trump was omitted, despite former Trump personal lawyer Michael Cohen testifying last week that he briefed her numerous times about a Trump skyscraper project in Moscow.

Also absent from the list were former senior White House officials, including chief of staff John Kelly and economic adviser Gary Cohn. Both spent more than a year in Trump’s inner circle and have featured prominently in books and other published accounts of conditions in the Trump White House.

The reasons for some prominent people being left off the House of Representatives investigators’ list were not immediately clear.

House Democrats say they have been careful to avoid conflict with the investigation by US Special Counsel Robert Mueller into Russian interference in the 2016 US election and possible coordination with the Trump campaign, as well as federal probes being led by the US Attorney’s Office in Manhattan.

House Judiciary Committee Chairman Jerrold Nadler told ABC on Sunday that Kelly could be included.

A committee aide said Monday’s list was only a first phase of document requests and more letters would be going out soon.

Eighty-one people, agencies and organisations were named by the committee as recipients of document requests, including Trump’s adult sons, Donald Jr (below) and Eric, as well as his son-in-law Jared Kushner, who is Ivanka’s husband and a White House adviser.

Representatives for the White House and Justice Department said the document requests were being reviewed.

At the White House, Trump was asked if he would cooperate with Nadler’s probe. “I cooperate all the time with everybody,” he said, adding, “You know the beautiful thing? No collusion. It’s all a hoax ... It’s a political hoax.”

Nadler’s committee hopes to determine whether Trump obstructed justice by possibly offering pardons or tampering with witnesses and by ousting perceived enemies, such as former FBI Director James Comey.

Trump fired Comey in May 2017 while he was leading an investigation into Russian meddling in the election. The probe was taken over by Mueller.

Comey was not on Monday’s list. Nor was Andrew McCabe, the former top FBI official who began an obstruction of justice and counterintelligence investigation involving Trump and his ties to Russia after Comey’s firing. Nor was Deputy Attorney General Rod Rosenstein, who appointed Mueller as special counsel.

- Reuters