A fourth woman has come forward with allegations of sexual misconduct against Neil deGrasse Tyson after the astrophysicist denied three previous accusations on Saturday.

The woman, who remained anonymous, told BuzzFeed Wednesday that Tyson drunkenly propositioned her at a 2010 event in New York City's American Museum of Natural History.

According to the report, Tyson "drunkenly approached" the woman at the event and allegedly proceeded to make "sexual jokes and propositioned her to join him alone in his office."

The woman claims she informed her employer of the encounter in order to decline a "proposed collaboration with Tyson."

Tyson did not return Fox News' request for comment on the latest allegation. Just last Saturday he had addressed each of the three previous accusations in a Facebook post entitled "On Being Accused." Tyson said many men who are accused of sexual misconduct in the #MeToo era are “presumed to be guilty by the court of public opinion.”

“I’ve recently been publically accused of sexual misconduct. These accusations have received a fair amount of press in the past forty-eight hours, unaccompanied by my reactions,” Tyson wrote. “In many cases, it’s not the media’s fault. I declined comment on the grounds that serious accusations should not be adjudicated in the press.”

“But clearly I cannot continue to stay silent. So below I offer my account of each accusation,” he added.

Fox Entertainment and National Geographic, the networks that air Tyson’s shows “Cosmos” and "StarTalk," announced Friday they will be conducting a “thorough investigation” into the allegations. "Cosmos" producers told us, "We are committed to a thorough investigation of this matter and to act accordingly as soon as it is concluded.”

A rep for Fox Broadcasting and National Geographic told Fox News, "We take these matters very seriously and we are reviewing the recent reports.”

Reps for the companies did not return Fox News' request regarding the latest allegation.

Tyson was host of "Cosmos: Possible Worlds" on Fox in 2014 and a new edition of the series was to air on National Geographic next year.

Tyson said he fully supports the investigation.

Last month, three women detailed to Patheos, a religion and spirituality website, Tyson’s alleged inappropriate sexual advances toward them. In a report published Nov. 29, Dr. Katelyn Allers, an associate professor at Bucknell University, recalled a 2009 meeting with Tyson, who she said felt her up while searching for Pluto on a tattoo of the Solar System on her arm.

“After we had taken the picture, he noticed my tattoo and kind of grabbed me to look at it, and was really obsessed about whether I had Pluto on this tattoo or not… and then he looked for Pluto, and followed the tattoo into my dress,” Allers told the site.

The 60-year-old said Saturday on his post that he didn’t remember searching for Pluto as part of her tattoo, but admitted “it is surely something I would have done in that situation.” He disputed reports that he had “groped” Allers.

“I was reported to have ‘groped’ her by searching ‘up her dress,’ when this was simply a search under the covered part of her shoulder of the sleeveless dress,” he said. “I only just learned (nine years after) that she thought this behavior creepy. That was never my intent and I’m deeply sorry to have made her feel that way. Had I been told of her discomfort in the moment, I would have offered this same apology eagerly, and on the spot.”

A second woman, Ashley Watson, told Patheos she was forced to quit her job as Tyson’s assistant after he made inappropriate sexual advances toward her. Watson claimed Tyson had “predatory tendencies” and once tried to convince her to have sex with him. Watson pointed to a time when Tyson invited her to his apartment to “unwind for a couple of hours” in 2018.

The former assistant said the meeting was uncomfortable and ended with an “awkward and incredibly intimate handshake.” She said she quit her job after “negative interactions” with her boss.

Tyson wrote in his Facebook post that he never touched Watson aside from the special handshake he had learned from a Native American elder on reservation land.

“I’ve never forgotten that handshake, and I save it in appreciation of people with whom I’ve developed new friendships,” he wrote, adding that he “apologized profusely” during his last meeting with Watson.

“I note that her final gesture to me was the offer of a hug, which I accepted as a parting friend,” he said.

The third woman, Tchiya Amet, accused Tyson of drugging and raping her when they were grad students at the University of Texas in 1984. Amet, who previously went by Staci Hambric, told Patheos that the alleged sexual encounter caused her to drop out of the astronomy program and seek therapy for post-traumatic stress disorder.

“I woke up in his bed; I was naked… When he saw that I had woken up, he got on top of me and mounted me, and I passed out again,” Amet recalled.

Tyson said he had a brief relationship with an astro-graduate student that quickly fizzled. He added that they ran into each other a few years later, when she was pregnant.

“More than thirty years later, as my visibility-level took another jump, I read a freshly posted blog accusing me of drugging and raping a woman I did not recognize by either photo or name,” Tyson wrote Saturday. “Turned out to be the same person who I dated briefly in graduate school. She had changed her name and lived an entire life, married with children, before this accusation.”

Tyson denied the drug and rape allegation and said it has been used “as a kind of solicitation-bait by at least one journalist to bring out of the woodwork anybody who had any encounter with me that left them uncomfortable.”

Fox News' Katherine Lam and The Associated Press contributed to this report.