Veteran journalist Mark Halperin sexually harassed women while he was in a powerful position at ABC News, according to five women who shared their previously undisclosed accounts with CNN and others who did not experience the alleged harassment personally, but were aware of it.

"During this period, I did pursue relationships with women that I worked with, including some junior to me," Halperin said in a statement to CNN Wednesday night. "I now understand from these accounts that my behavior was inappropriate and caused others pain. For that, I am deeply sorry and I apologize. Under the circumstances, I'm going to take a step back from my day-to-day work while I properly deal with this situation."

MSNBC, where Halperin makes frequent appearances on "Morning Joe," said early Thursday that Halperin would leave his roles at that network and as an analyst at NBC News.

"We find the story and the allegations very troubling," MSNBC said in a statement. "Mark Halperin is leaving his role as a contributor until the questions around his past conduct are fully understood."

Widely considered to be one of the preeminent political journalists, Halperin, 52, has, among other career highlights, been political director at ABC News; co-authored the bestselling book "Game Change," which was made into an HBO movie starring Julianne Moore as Sarah Palin; and anchored a television show on Bloomberg TV. He is featured in Showtime's "The Circus," a show that chronicled the 2016 campaign cycle and the early days of the Trump presidency, and has a project in development with HBO, which, like CNN, is owned by Time Warner.

But women who spoke to CNN say he also had a dark side not made public until now. The stories of harassment shared with CNN range in nature from propositioning employees for sex to kissing and grabbing one's breasts against her will. Three of the women who spoke to CNN described Halperin as, without consent, pressing an erection against their bodies while he was clothed. Halperin denies grabbing a woman's breasts and pressing his genitals against the three women.

Related: The (incomplete) list of powerful men accused of sexual harassment after Harvey Weinstein

The women who worked with Halperin and who spoke with CNN did not report to Halperin. However, Halperin made many decisions about political coverage at ABC News, and had a voice in some critical personnel decisions. None of the women have said, though, that he ever promised anything in exchange for sex, or suggested that he would retaliate against anyone.

Still, while they no longer work with him, Halperin continues to wield influence in politics and media. The women who spoke to CNN said it was for this reason that they shared their accounts on the condition of anonymity. Others also said they still feel embarrassed about what happened to them and did not want to be publicly associated with it.

"Mark left ABC News over a decade ago, and no complaints were filed during his tenure," ABC News said in a statement provided to CNN after this article was published.

The first woman told CNN she was invited to visit his office in the early 2000s, when he was political director at ABC News, to have a soda, and said that while she was there with him he forcibly kissed her and pressed his genitals against her body.

"I went up to have a soda and talk and -- he just kissed me and grabbed my boobs," the woman said. "I just froze. I didn't know what to do."

When she did make her way out of his office, the woman told a friend at ABC News what had happened. That friend told CNN she remembered the woman telling her about the incident and seeing her visibly shaken.

The second woman, another former ABC News employee, described a similar experience in his office during the 2004 campaign cycle. This woman said she was around 25 years old then, and wanted to be a "campaign off-air" -- ABC News' term for one of the reporters who travel embedded with presidential campaigns -- so she reached out to Halperin, who was a part of the decision-making process regarding those assignments at the time.

"The first meeting I ever had with him was in his office and he just came up from behind -- I was sitting in a chair from across his desk -- and he came up behind me and [while he was clothed] he pressed his body on mine, his penis, on my shoulder," this woman told CNN. "I was obviously completely shocked. I can't even remember how I got out of there -- [but] I got out of there and was freaked out by that whole experience. Given I was so young and new I wasn't sure if that was the sort of thing that was expected of you if you wanted something from a male figure in news."

The woman said Halperin continued to express a sexual desire for her in subsequent visits, despite being rebuffed.

"It was more like him coming up too close to me and sort of along the lines of hugging me," she explained.

She also alleged that Halperin propositioned her for sex on the campaign trail.

"He would say, 'Why don't you meet me upstairs?' And I would say, 'That's not a good idea.' And he would push the request further," the person said. "Eventually I would just ignore him and go about my business."

One of the woman's friends has told CNN that the woman told her about the first incident, in Halperin's office. She said her friend had told her some time after the incident that Halperin had pressed his genitals against her while she was seated in his office, but did not recall being told about unwanted touching during subsequent visits or the alleged propositions for sex.

A third woman, also a former ABC News employee, told CNN she was on the road with Halperin when he propositioned her.

"I excused myself to go to the bathroom and he was standing there when I opened the door propositioning [me] to go into the other bathroom to do something," she said. "It freaked me out. I came out of the ladies' room and he was just standing there. Like almost blocking the door."

A fourth woman who worked with Halperin and was junior to him told CNN he once asked her late at night on the campaign trail to go up to his hotel room with him, and that she believed him to be propositioning her. She declined.

The fifth woman who spoke to CNN was not an ABC News employee at the time of the incident she alleges. She was not comfortable sharing specifics of her story for publication, but said Halperin, while clothed, placed his erect penis against her body without consent.

The women who spoke to CNN said that they did not report Halperin's behavior to management either because they feared retribution, given the level of power Halperin had at ABC and in the industry, or because they were embarrassed. In some cases, their fear of him and the sway he holds remains to this day.

The woman in the first account, however, said she told a mentor at ABC News who said he wanted to escalate the issue to management. It is unclear if that ever occurred.

CNN's investigation found that Halperin allegedly exhibited this type of behavior from the 1990s to the mid-2000s. CNN has not learned of any incidents after Halperin left ABC News.

Halperin joined ABC News in the late 1980s. In 1997 Halperin was named political director of ABC News, and rose to prominence with the advent of The Note, a morning digest newsletter previewing the day in politics. The Note became a must-read for industry professionals, and it catapulted him to the upper echelons of the political scene.

Halperin left ABC News in 2007 for Time magazine and joined Bloomberg in 2014 for a reported salary of $1 million. At Bloomberg, he co-anchored "With All Due Respect" with journalist John Heilemann. The show was simulcast on MSNBC for a period.

Related: Mark Halperin leaves Bloomberg

Halperin also found great success writing books. In 2010, he co-authored "Game Change" with Heilemann. The duo later published "Double Down: Game Change 2012," reportedly receiving a multi-million dollar advance. Halperin and Heilemann are currently working on a third installment about the 2016 election.

"For the last 11 years, I have had to watch this guy find success in every other news organization," one of the women who said she experienced harassment told CNN.

The allegations against Halperin come weeks after Hollywood mogul Harvey Weinstein was first publicly accused of sexual harassment and assault -- allegations that have prompted multiple police departments to launch investigations, the Academy of Motion Picture Arts to expel him, and his firing from the company he co-founded. (Weinstein denies all allegations of non-consensual acts.)

While the allegations against Halperin do not mirror the allegations against Weinstein, the fact that the women who spoke with CNN have chosen to do so now does reflect the larger discussion in entertainment, media, politics and other industries since the Weinstein scandal began. Women -- and men -- are talking about things that have long been rumored but have never been brought to light. Some people are feeling emboldened to tell those stories now. Others are looking back and regretting the things they didn't do.

One person who formerly worked with Halperin told CNN that while they were not aware of the extent of the alleged harassment, they believe they had heard enough to warrant reporting the whispers to management.

"In retrospect, I was such a coward," the person said. "I wish I said something. I wish I had done something."