A lawyer for Jared Kushner argued that anti-nepotism laws do not apply to the West Wing
Donald Trump's son-in-law has been named as senior adviser to the President in the new US administration.
Jared Kushner, who is married to Mr Trump's daughter Ivanka, has no political experience but has been a senior figure on the billionaire's team during the campaign.
Like his father-in-law, Mr Kushner is a New York-based real estate magnate with a wide range of business dealings that could be challenged as posing potential conflicts of interest.
The 35-year-old is also a publisher of the New York Observer weekly newspaper.
Mr Trump said his son-in-law will serve as senior White House adviser.
"Jared has been a tremendous asset and trusted adviser throughout the campaign and transition and I am proud to have him in a key leadership role in my administration," he said in a statement.
His appointment could also be challenged by an anti-nepotism law that bans presidents from hiring family members.
However, a lawyer for Mr Kushner argued Monday that the 1967 law does not apply to the West Wing and pointed to a later congressional measure which allows the President "unfettered" and "sweeping" authority in hiring staff.
Jamie Gorelick added that he would step down as CEO of the family's real estate company and from the New York Observer.
She also said Mr Kushner would recuse himself "from particular matters that would have a direct and predictable effect on his remaining financial interests".
The son-in-law has continued to be influential on the transition team, reportedly playing a role in coordinating contacts with foreign leaders and shaping Middle East policy.
Mr Kushner's powerful role in the new administration emerged as Mr Trump confidently predicted that all his high-profile appointments would be approved by the US Senate.
Senators are to question the President-elect's picks for the Secretary of State, attorney general and head of homeland security, as at least nine of his appointments appear before committees from Tuesday.
The President-elect held talks with several business and media figures at Trump Towers on Monday, but the day was overshadowed by his angry reaction to an attack by actress Meryl Streep at the Golden Globes award ceremony.
He also met Senate Majority Leader Mitch McConnell to discuss the confirmation hearings and repealing and replacing President Barack Obama's healthcare law.
The leader of the Senate Republicans said he expected six or seven of Trump's picks - "particularly the national security team" - to be "in place on day one".