The director of a globally recognized research institute at Mount Sinai's Icahn School of Medicine denigrated female employees and created an environment that pushed them from their positions, according to a federal lawsuit.

The lawsuit, from seven current and former female employees and one male former employee, accuses Mount Sinai and several employees affiliated with the school's Arnhold Institute for Global Health of creating an environment hostile to existing workers, many of them women in their 40s or older, and giving preferential treatment to younger, male researchers.

The suit, which was first reported by Science magazine, was filed April 26 in U.S. District Court for New York's southern district. Court papers describe the institute's director, Dr. Prabhjot Singh, as "abusive, dismissive and hostile."

Singh was named to the role in 2015 by Dr. Dennis Charney, dean of the Icahn School, whom the suit alleges passed over a researcher recommended by a school search committee. Singh, then 32, was recruited from Columbia University, where he was a faculty member and a director at the university's Earth Institute, according to the school's announcement at the time.

Plaintiffs in the lawsuit include Dr. Holly Atkinson, a former medical journalist who built and directed the institute's human rights program. According to the suit, Singh demoted Atkinson and she was told she could keep her job only if she took a 40% pay cut. Atkinson left the institute in 2016 and is now a clinical professor at the CUNY School of Medicine. Another plaintiff, Dr. Natasha Anushri Anandaraja, is a pediatrician who was a founding member of the institute in 2005 and directed its global health education initiatives. The lawsuit says Singh insulted and demoted Anandaraja before she left in 2016.

Research at the institute, which the lawsuit calls the "crown jewel" of Mount Sinai, has received national recognition. In 2013 the institute received a $12.5 million grant from the Arnholds, a prominent banking family.

But under Singh's leadership, senior female employees were "demoted, their well-developed and effective programs were denigrated and defunded, and they were forbidden from speaking to their former colleagues," according to a press release from law firm McAllister Olivarius, which is representing the employees. "This was not just a normal office disagreement about goals or methods," the document says. "Dr. Singh publicly disparaged the competence of women in senior leadership and made their working lives miserable until they were finally forced out."

In a statement, a spokeswoman for Mount Sinai denied the allegations and said the health system will "vigorously defend the action."

The lawsuit also names Charney, a prominent biological psychiatrist and researcher. Singh was Charney's protégé, the lawsuit says, adding that the two men share a "tough guy" management style. Charney disparaged a female candidate for the institute director position, the suit alleges.

The Mount Sinai spokeswoman said the school "promptly initiated an internal review" when institute employees brought concerns to its attention last year, "after which appropriate steps were taken."

The lawsuit acknowledged Mount Sinai's review, which it said created an oversight committee to guide Singh's management but did not seek further disciplinary action.