The video, posted on a rival station's Web site, shows veteran WMAQ-TV reporter Amy Jacobson wearing a halter bikini top and towel near the pool at Craig Stebic's suburban Plainfield home.
Jacobson's two young children and a bare-chested Stebic are also shown in the video, shot Friday.
Jacobson's attorney, Kathleen Zellner, told the Tribune she was concerned the media would distort the contents of the tape.
"She wasn't fired. There was no drinking. No one was sitting in a hot tub. She wasn't anywhere near him (Craig Stebic)," Zellner said. "(Stebic's) sister invited her to drop by."
WMAQ-TV's general manager Larry Wert said Jacobson and NBC have parted ways, leaving open the possibility that she may have resigned after more than ten years at the station, reports CBS 2 News in Chicago.
Staff members received a memo Tuesday afternoon from station officials saying that "Amy Jacobson is leaving NBC 5 News, effective immediately," according to the Chicago Tribune, which obtained a copy.
"Amy's contribution as a reporter over the last ten years are numerous," the memo said. "Her hustle and passion for news have given us an edge on many top stories. She's worked long hours on many days, and we appreciate all she's done."
Jacobson had not appeared on air since news of the video broke Monday.
"If you're a reporter, you don't put yourself in that kind of situation, especially if you're covering the story," said Larry Stuelpnagel, assistant professor at Northwestern University's Medill School of Journalism and Department of Political Science.
Jacobson was assigned to cover the disappearance of Stebic's wife, Lisa, who still lived with her husband while the two went through a divorce. No one has been charged in the case, which has generated high interest here since the young mother of two disappeared on April 30th.
Stebic's husband was the last person to see her, but police have said he is not a suspect in the disappearance. On the day she disappeared, Lisa Stebic had mailed off a petition seeking to remove her husband from the home. In the divorce case, she accused him of being "unnecessarily relentless, cruel, inconsiderate, domineering and verbally abusive."
Jacobson told her bosses that she was on her way with her sons to go swimming at a local club when Craig Stebic's sister asked her to go to his house to talk about the case, the Chicago Sun-Times reported.
WBBM News Director Carol Fowler said the video was recorded Friday, but she declined to say how the CBS affiliate got the tape. Station officials held the video while they debated its newsworthiness, Fowler said.
The station decided to air the video once "it was clear (Jacobson's) own conduct was in question by the people she worked for," Fowler said.
Jacobson has been a general assignment reporter for WMAQ since 1996, according to her biography on the station's Web site. She has also reported in Detroit; El Paso, Texas; Tucson, Ariz.; and Alexandria, Minn.