Jeffrey Mayer via Getty Images From left: Rob Lowe, wife/makeup artist Sheryl Berkoff, John Owen Lowe and Samantha Schwab at The Comedy Central Roast of Rob Lowe at Sony Studios on August 27, 2016. Schwab has been working as a volunteer in the White House Office of Legislative Affairs this spring.

Samantha Schwab, the 21-year-old granddaughter of brokerage billionaire Charles Schwab, has been working in the Trump White House Office of Legislative Affairs.

The White House won’t say why Schwab was hired, or give details on her work for the Trump administration. HuffPost learned of Schwab’s job from a source, who shared correspondence between Schwab’s official White House email account and congressional offices.

The header on Schwab’s White House email address says “Volunteer” in parentheses after her name, suggesting she may not be a full-time staffer. She is not an official White House intern. This is what her email looks like:

The Huffington Post

It’s generally illegal for federal agencies to use unpaid labor, with a few notable exceptions. These include the prestigious (but unpaid) White House internship program, as well as a volunteer program to decorate the White House for holiday tours.

Schwab’s billionaire grandfather founded the eponymous brokerage firm in 1971 and contributed $1 million to Trump’s record-breaking inaugural fundraising committee. HuffPost contacted him for comment through his family foundation, but did not receive a reply.

Vanity Fair Samantha Schwab at the Republican National Convention in Cleveland last summer.

Samantha Schwab attended the 2016 Republican National Convention in Cleveland as part of the California delegation. She is an undergraduate at Stanford University in California, where a student directory lists her major as economics. Her grandfather, who supported Jeb Bush in the 2016 GOP presidential primary, holds a Stanford economics degree.

Samantha Schwab would appear to be eligible for the White House internship program. But the first class of Trump White House interns doesn’t start until May 30. Applications were due in April, and Schwab has been at the legislative affairs office since at least March, according to her emails.

Schwab, reached by phone Tuesday, said she did not have time to talk, and asked HuffPost to call later. Subsequent calls were diverted to an operator, and messages were not returned. HuffPost also sent detailed questions about Schwab’s job to the White House, but did not receive a response.

Ethics experts said Schwab’s position raises a number of red flags, including the same issues Ivanka Trump encountered during her brief stint as a “volunteer” adviser to her father, the president.

Schwab’s “volunteer” position, and the administration’s secrecy about it, are “highly unusual and reeking of patronage,” said Richard Painter, who served as former President George W. Bush’s ethics czar. In order to address potential conflicts of interest, Schwab should formally agree to ethics rules for all White House employees, regardless of whether she is being paid, Painter added.

“If someone has a White House email and they’re coming into work every day and corresponding with congressional offices, then they are an employee,” Painter said. “Nobody can just go into a White House job and say they’re a volunteer and not be subject to ethics rules.”

The practice of giving jobs to relatives of important donors is hardly a new phenomenon in Washington. In 2013, then-President Barack Obama’s summer intern class Included children of billionaire campaign donor Steven Rattner and former Treasury Secretary Larry Summers.

But what’s new in the Trump administration is a widespread tolerance for conflicts of interest, worsened by a lack of transparency that includes Trump’s failure to disclose his tax returns and his refusal to make public White House visitor logs.

Schwab’s position also raises the question of whether it violates the Antideficiency Act, a law that prohibits the federal government from accepting volunteer services. The purpose of the law is to ensure that if the president wants to hire more people, he must ask Congress, which appropriates money for Executive Branch personnel.

“There’s a special exception made to the Antideficiency rules for education-based internships, like the White House internship program,” said Kathleen Clark, a law professor and government ethics expert at Washington University in St Louis. “But if you didn’t have the exception, what you’d have here is the Executive Branch using unpaid labor, which is not accountable to Congress.”

Cases like Schwab’s also reveal larger and more systemic ethics issues within the administration, said Alex Howard, of the nonprofit Sunlight Foundation.

“By deciding to lift the traditional caps on inaugural donations and accept unlimited amounts from each individual, Trump opened himself up to questions like this one,” Howard said in an interview.

Howard, a former HuffPost reporter, also emphasized how valuable working in the White House is for a young person’s career.

“The White House is the top of our executive branch, and it is unrivaled in terms of prestige, power and influence,” Howard said. “So the things [staffers] learn, and the connections they make are basically priceless.

“But when someone is given this incredibly valuable experience in secret, because of their family’s political contributions, it erodes the public trust in the entire government,” he said.