It was another starry night in Hollywood. In a white-walled room at the Milk Studios art gallery, where a lone violinist played before a projected animation, musician Moby, artist Shepard Fairey and Los Angeles mayor Eric Garcetti reportedly mingled with about 200 guests.

On display were artworks that combine canvas, yupo paper, wood and metal with oil, acrylic, ink and the written word. Organizers hope they will sell for up to half a million dollars – unusually high for an emerging artist. But then, this artist also happens to be son of the president of the United States.

Hunter Biden’s potentially lucrative new career – he is represented by the Georges Bergès Gallery in New York, which credits him with “powerful and impactful paintings ranging from photogenic to mixed media to the abstract” – is presenting ethical headaches for a White House that has promised to lead by example.

Experts have raised alarms that individuals might buy the artworks – expected to fetch between $75,000 and $500,000 – to try to curry favor and gain influence with Joe Biden. They also accuse Hunter of trading on his father’s name and position in a manner that, while not illegal, flouts ethical norms.

“I find it deeply troubling,” said Walter Shaub, who was director of the Office of Government Ethics under President Barack Obama. “Merely following the incredibly weak ethics rules that we have doesn’t win you any points and the legalistic approach blinds you to obvious commonsense problems. And here we have an obvious problem.

“We’ve got a family member clearly trading on his father’s name. The man has never sold a piece of art before, has never even juried into a community centre art show, but suddenly he’s selling art at fantastical prices. There is simply no way anybody paid $75,000 for anything other than his name.”

Biden has always been a fierce defender of Hunter, 51, who has been dogged by controversies for years and whose tax affairs are currently under investigation by the justice department. Donald Trump’s attempts to weaponise Hunter’s problems for political gain in the 2020 presidential election fell flat.

Earlier this year Hunter published a memoir in which he detailed his struggle with alcoholism and drug abuse and denied wrongdoing in joining the board of Burisma, a gas company in Ukraine, where he earned more than $50,000 a month from 2014 to 2019. Again, he did not inflict political damage on his father as some feared.

But his latest pursuit, painting, could prove more complicated. Hunter said in a New York Times interview last year that he took it up as a hobby during his recovery from addiction and found solace in art when he was at the centre of Trump’s 2019 impeachment trial.

In July he told the Nota Bene: This Week in the Art World podcast that art prices are “completely subjective”, insisting: “Look, man, I never set my prices – what my art was going to cost, what it costs or how much it would be priced at. I would be amazed, you know, if my art had sold at, um, you know, for $10.”

The sale of his work, however. appears to be cutting through as a media narrative in a way that lurid rightwing conspiracy theories never did. Just as President Jimmy Carter’s younger brother marketed and sold “Billy Beer” in 1977, Hunter faces accusations that he is cashing in.

Shaub, now a senior fellow at the Project on Government Oversight watchdog, commented: “You hear people trying to justify it by saying, ‘Well, of course, he’s famous, he’s the president’s son,’ but that’s the exact problem because he may not be in public office and there may be no laws that apply to him but he is a citizen whose father happens to be the leader of the country and so he has a patriotic duty to not run around trying to capitalise on that relationship.

“Sure, he’s not a criminal if he fails to comply with that duty, but he’s not a patriot either. He’s not a man who cares about a country that has just been through a four-year ethical nightmare. He sees an opportunity for profiteering and says, ‘Well, you know, it’s legal. I’m just going to do it. Who cares what that does to my country?’”

The conflict-of-interest concerns cast a shadow over efforts by the president – who likes to vow “my word as a Biden” – to show the world that America has turned the corner after the constant allegations that Trump’s business and family benefited from his office, including the appointment of his daughter and son-in-law to senior White House positions.

Biden issued a memorandum establishing fighting corruption as a core national security interest. His administration responded to the Pandora Papers by promising to push for greater transparency in financial systems.

It sought to pre-empt questions over Hunter’s art by striking an agreement, first reported by the Washington Post in July, under which the gallery owner, Georges Bergès, would set the prices of the art and not reveal who bid on or bought it, as well as rejecting offers that seemed extortionate.

But there is no mechanism to monitor the agreement. Critics say Hunter’s presence at the recent gallery event in Hollywood undercut claims that neither he nor the White House would know the identity of buyers. And Garcetti, who also attended, is Biden’s nominee to be the next US ambassador to India and a former national co-chair of his 2020 presidential campaign.

The issue was given short shrift this week by Jen Psaki, the White House press secretary.

She told a reporter at the daily briefing: “It still is the purview of the gallerist. We still do not know and will not know who purchases any paintings. And the president remains proud of his son.” When the reporter tried to follow up, Psaki interjected sharply: “Did you have another question on something else?”

Shaub condemned her manner as “surly” and described the agreement to keep buyers anonymous as “an insult to our intelligence”. He explained: “Anybody who spends tens or hundreds of thousands of dollars to buy art because it was created by the president’s son is going to be very open and vocal about the fact that they bought it. It’s going to be the showpiece at cocktail parties and so that information will eventually come out. This is a farce.”

Some commentators have argued that transparency would work better than secrecy, allowing the public to know whether a buyer such as a political lobbyist had paid a suspiciously high price. When the Guardian called the Georges Bergès Gallery, it was told to send an email and did so, but did not receive a reply. When the Guardian called the Milk Studios, which hosted Hunter’s show, a man twice answered and twice hung up.

Ethics expert Kathleen Clark, a professor at Washington University School of Law, joined criticism of the arrangement. “It’s really unfortunate that Hunter Biden has chosen to attempt to make money in a way that is vulnerable to influence peddling.

“Now, he’s an adult and the ethics standards that bind elected officials and civil servants don’t apply to him directly. On the other hand, not all forms of compensated work have this kind of vulnerability but this kind of work does because it’s so difficult to know exactly what the value of a painting is.”

The previous White House set a historically low bar, Clark added. “The Trump administration gave the impression that they were attempting to be unethical, like that was the goal, like they were seeking some kind of championship bid in unethical if not criminal conduct. It’s nothing like that. But it still could be a disappointment when the Biden administration doesn’t live up to what it might do in terms of transparency, for example.”

Indeed, the sheer breadth and depth of Trump scandals that captivated the media for four years might have partially shielded Biden and Hunter from sustained scrutiny. A recent book on the Biden family by the Politico journalist Ben Schreckinger presents evidence that some emails allegedly leaked from Hunter’s laptop regarding business deals were genuine and not, as widely assumed, planted by Russian intelligence.

Shaub suggested that many people are blinded to the ethical problem of the artwork for two reasons. “One is just the hyper-partisanship that has evolved in our country and so people who voted for Biden run around saying, ‘Well, it’s not as bad as Trump.’

“Of course it’s not even close to as bad as Trump but ‘better than Trump’ should never, ever, ever become the standard in this country because that’s saying, ‘I’m better than the absolute worst that prior to 2016 you couldn’t have even conceived of.’”

He continued: “The second thing that’s blinding people is that there was a lot of unfair smearing of Hunter Biden by very well-funded political actors who were completely disingenuous in their ridiculous accusations. I guess that worked well with their base but it really clouded the issue because the truth is Hunter Biden is not the villain these political actors make him out to be.

“But he’s also not the upstanding citizen that the White House wants you to believe. This is a man whose entire life has been is based off of making money on his father’s political career and that is not something we should embrace in this country and celebrate and tolerate. So two things can be true at the same time.”

US allies around the world have been looking at the US for evidence that the country has stabilized in the aftermath of Trump’s presidency, Shaub said. “Yeah, we have a new administration that isn’t rampantly thumbing its nose at the rule of law, but it is going right up to the line and saying, if it’s legal, we’re going to do it and we’re not going to focus on reforms, we’re not going to focus on setting a squeaky clean tone, we’re going to go back to the way things were before Trump.”