Jefferson Siegel/NY Daily News via Getty Images(NEW YORK) — A former New York City obstetrician, who was stripped of his medical license after pleading guilty to serial sexual-assault charges, is being re-investigated after numerous complaints have flooded the Manhattan District Attorney’s offices since the wife of former Democratic presidential contender Andrew Yang went public with accusations against the physician.Robert Hadden, who pleaded guilty in 2016 to a single felony count of criminal sexual contact and a misdemeanor count of forcible touching as part of a deal that kept him out of prison, is the focus of a new investigation launched by New York prosecutors, officials said.“We admire the courage of the survivors who have recently shared their stories,” Danny Frost, a spokesman for Manhattan District Attorney Cy Vance, said in a statement Friday to ABC News. “Their voices will be heard and the abuse they suffered will be thoroughly investigated.”Frost said two senior prosecutors have been assigned to investigate new allegations of sexual misconduct made against Hadden and are “in touch with a representative of a number of survivors.”Hadden could not be immediately reached for comment.Dozens of women have come forward with public accusations against Hadden since Evelyn Yang, the wife of Andrew Yang, alleged in a January interview with CNN that Hadden assaulted her in 2012 while she was pregnant with her first child.“It started with inappropriate questions around how intimate I was with my husband, sexual activity, just very inappropriate, probing questions that were unrelated to my health,” Evelyn Yang told CNN. “The examinations became longer, more frequent, and I learned that they were unnecessary most of the time.”She alleged that the abuse escalated when she was seven months pregnant.“I was in the exam room, and I was dressed and ready to go,” she said. “And then at the last minute, he kind of made up an excuse. He said something about I think you might need a C-section. And he proceeded to grab me over to him and undress me and examine me internally, ungloved. And at first, I was a little bit like what’s going on here?” she said.Evelyn Yang was among 19 women who accused Hadden of sexual assault in the previous criminal investigation.She testified before a grand jury which indicted Hadden on multiple felony sex charges stemming from the assaults of six of the women.Hadden, a former obstetrician-gynecologist at Columbia’s NewYork-Presbyterian Hospital, negotiated a “conditional discharge” plea deal in 2016 that required him to give up his medical license and register as a low-level sex offender, but allowed him to dodge any jail time or probation.Following Hadden’s plea deal, Vance released a statement saying “our primary concern was holding him accountable and making sure he could never do this again.” He noted that had Hadden gone to trial, a conviction was not guaranteed.“While we stand by our legal analysis and resulting disposition of this difficult case, we regret that this resolution has caused survivors pain,” Vance said in his statement.Scott Berkowitz, president for the Rape, Abuse & Incest National Network (RAINN), said in a statement that his organization is “encouraged by the District Attorney’s decision to open a new investigation.”Anthony T. DiPietro, a malpractice attorney who represents several of Hadden’s victims, tepidly applauded Vance’s decision to open a new investigation against Hadden.“I’m glad the DA has decided to support the survivors and finally prosecute Hadden, but it’s not enough,” DiPietro said in a statement to ABC News on Friday.In 2018, DiPietro filed a lawsuit against Columbia and its affiliated hospitals, accusing them of covering up Hadden’s behavior for decades.“Columbia University has been hiding evidence of Hadden’s sexual abuse for the past 25 years,” DiPietro alleged. “In order to make sure this doesn’t happen again, I’m calling for the DA to open a criminal investigation into Columbia University for the role it played in enabling, aiding, abetting, and covering up two decades of sexual abuse.”A Columbia University spokesperson declined to comment Friday on the litigation, but added, “We condemn sexual misconduct in any form and will cooperate fully with any request for information from the district attorney’s office related to Robert Hadden.”Copyright © 2020, ABC Audio. All rights reserved.