Former New York City Mayor Rudy Giuliani is lobbying President Donald Trump on unproven coronavirus treatments such as hydroxychloroquine, according to a Washington Post report.

Giuliani is also touting a stem cell treatment for COVID-19, which he describes as removing "placenta killer cells."

He has also been pushing for the malaria drug on his podcast and on his Twitter feed.

Last week, Twitter deleted a tweet by Rudy Giuliani for spreading coronavirus misinformation.

The Post reports that Giuliani has consulted with a controversial Long Island doctor with a conservative following and a pharmacist who previously pleaded guilty for conspiring to extort Steven Seagal.

"What you're seeing is an effort to regain relevance," Giuliani's biographer told The Post.

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After receding from the limelight once the Russia investigation and impeachment wrapped up, former New York City Mayor Rudy Giuliani is making headlines again, lobbying President Donald Trump on untested coronavirus treatments, according to a new report from The Washington Post.

Giuliani, 75, has served as Trump's personal attorney on a pro bono basis throughout the first term thus far, most often dispatched to defend the president on television amid the Russia and Ukraine scandals.

Now, Giuliani is pushing for the malaria drug hydroxychloroquine and what he describes as removing "placenta killer cells" in a stem cell treatment for COVID-19. As the Post put it, the former mayor is attempting to position himself as "personal science adviser" to the president.

Both hydroxychloroquine and the stem cell treatment are unproven and have yet to receive FDA approval to treat the coronavirus.

Last week, Giuliani had a tweet removed for violating Twitter's misinformation policy when he promoted the anti-malaria drug.

A couple weeks ago in Nevada, a man died from trying to immunize himself from the coronavirus with the drug by ingesting fish tank cleaner. His wife later said she and her husband thought it was safe because "Trump kept saying it was basically pretty much a cure."

Trump said he would take hydroxychloroquine to keep himself immune from COVID-19 during a White House press briefing last week.

Giuliani is joining a growing number of Trump confidants backing the drug, which The Post reports is "worrying health experts who fear such comments undermine efforts to slow the virus's spread and downplay the risks of the unproven treatments."

The former mayor told The Post he has spoken to Trump about the potential treatment "three or four times," and has sought medical advice from a controversial Long Island doctor with a conservative following and a pharmacist who previously pleaded guilty for conspiring to extort Steven Seagal.

Andrew Kirtzman, Giuliani's biographer who is working on a second book on the principal, contextualized Rudy's resurgence in an interview with The Post.

"​He's been out of the news and out of the limelight since the end of the impeachment drama," Kirtzman said. "What you're seeing is an effort to regain relevance."