A high-ranking federal scientist and one of the leading vaccine experts in the U.S. said in a withering statement on Wednesday that he was fired from his post as director of the Department of Health and Human Services' Biomedical Advanced Research and Development Authority because he questioned and resisted President Donald Trump's promotion of untested Covid-19 treatments, particularly hydroxychloroquine.

Dr. Rick Bright, who was moved to a post at the National Institutes of Health, said he believes the "transfer was in response to my insistence that the government invest the billions of dollars allocated by Congress to address the Covid-19 pandemic into safe and scientifically vetted solutions, and not in drugs, vaccines, and other technologies that lack scientific merit."

"A global pandemic is not the time to shuffle personnel, or contradict and remove experts for wanting to do their job well. These reports are incredibly disturbing and I will be pushing for answers."

—Sen. Patty Murray

"I also resisted efforts to fund potentially dangerous drugs promoted by those with political connections," Bright added. "Specifically, and contrary to misguided directives, I limited the broad use of chloroquine and hydroxychloroquine, promoted by the administration as a panacea, but which clearly lack scientific merit."

Bright, who was playing a leading role in the effort to develop a vaccine for the novel coronavirus, said he decided to speak out because the Trump administration has put "politics and cronyism ahead of science" in its response to the Covid-19 pandemic.

Earlier this month, despite warnings from public health experts, Trump touted hydroxychloroquine as a "game-changer"—though the president has toned down his promotion of the anti-malaria drug in recent days after a study found it offered no benefit to Covid-19 patients.

Trump claimed during a press briefing Wednesday evening that he has "never heard of" Bright, who said in his statement that he "resisted efforts to provide an unproven drug on demand to the American public."

"These drugs," said Bright, "have potentially serious risks associated with them, including increased mortality observed in some recent studies in patients with Covid-19."

Trump says he has never heard of Dr. Rick Bright, the HHS coronavirus official who says he was pushed out because of his resistance to Trump's hydroxychloroquine push pic.twitter.com/Ep7uBk9BHP — Aaron Rupar (@atrupar) April 22, 2020

In a statement late Wednesday following news of Bright's removal, Sen. Patty Murray (D-Wash.) said "we need to be listening to experts and science, not pushing them aside."

"A global pandemic is not the time to shuffle personnel, or contradict and remove experts for wanting to do their job well," Murray said. "These reports are incredibly disturbing and I will be pushing for answers."