The TV doctor Mehmet Oz’s move into politics appears to have been a step too far for administrators at Columbia University, who have quietly purged his presence from their website as the Republican seeks to represent Pennsylvania in the US Senate.

For more than seven years, the private New York university has resisted calls to cut ties with Oz, a heart surgeon who has used his TV platform to push medicines ranging from ineffective diet pills to discredited Covid treatments.

According to the Daily Beast, that changed this year, within weeks of Oz, 61, declaring his candidacy for the Senate seat being vacated by the Republican Pat Toomey.

Oz, a friend and acolyte to Donald Trump, who has endorsed him, no longer has personal pages on the website of Columbia’s Irving Medical Center, the Beast reported, noting he once held senior titles including director of surgery and director of integrated medicine.

Columbia did not respond to an inquiry from the Guardian.

The Beast suggested the decision was political. Faculty leaders stuck with Oz through numerous medical controversies, including his 2014 Senate testimony regarding his plugging of “sham” diet pills on The Dr Oz Show, which ended its 13-season run this year.

Following the testimony, a group of distinguished physicians wrote to Columbia, claiming Oz had “repeatedly shown disdain for science and for evidence-based medicine” and shown “outrageous conflicts of interest or flawed judgements about what constitutes appropriate medical treatments, or both”.

“Worst of all,” the letter continued, “he has manifested an egregious lack of integrity by promoting quack treatments and cures in the interest of personal financial gain.”

One of the signatories to the letter, which Columbia rebuffed, was Scott Atlas, who would himself be criticized for spreading misinformation as coronavirus adviser to the Trump administration.

In 2011, the federal Food and Drug Administration (FDA) branded as “misleading and irresponsible” a report on the Dr Oz Show suggesting apple juice contained dangerously high levels of arsenic.

The prominent medical ethicist Dr Arthur Caplan, who in 2014 accused Oz of “promoting fairy dust”, told the Guardian he was not surprised Columbia had “quietly eliminated” Oz.

“They won’t have a press conference in the middle of this guy running for the Senate saying they were throwing him out … it could be seen as trying to influence an election, it could be risking bad blood should he become a senator,” said Caplan, professor and founding head of the Grossman School of Medicine Division of Medical Ethics at New York University.

“My question becomes, ‘What took so long?’ He’s been a huge danger to public health in the US and around the world for a long time with respect to quack cures for Covid and touting quackery to treat diseases.

“I was among the voices saying he had to be removed years ago. And I still think it’s the right thing to do because he really has forfeited credibility as a doctor. Whether that will matter in terms of the election, we shall see.

“I think it should, I doubt it will.”

The Oz campaign did not immediately respond to a request for comment.

Polling for the Pennsylvania Republican Senate primary on 17 May shows Oz trailing David McCormick, a hedge fund manager, by between 2% and 11%, according to Real Clear Politics.

Many analysts see the race as a test of Trump’s grip on the Republican party. At a rally in Selma, North Carolina, earlier this month, the former president called Oz a “great guy, good man … Harvard-educated, tremendous, tremendous career and they liked him for a long time.

“That’s like a poll. You know, when you’re in television for 18 years, that’s like a poll, that means people like you.”

Trump and Oz will appear at a rally in Greensburg, Pennsylvania on 6 May.

Trump previously endorsed Sean Parnell, who withdrew after being accused by his wife of abusive behavior, which he denied.