HARRISBURG — Senate Minority Leader Jay Costa (D., Allegheny) on Thursday called for Sen. Daylin Leach to resign following a law firm’s “preliminary report” on its investigation into sexual assault or harassment allegations levied against the Montgomery County Democrat.

The report described “a lengthy pattern of troubling behavior spanning several years regarding Sen. Leach’s interactions with a number of women,” according to a statement released Thursday by the Senate Democratic Caucus. Costa, in the statement, said the probe found evidence of “irresponsible behavior and an unacceptable workplace.”

Senate Democrats on Wednesday met privately with lawyers from Eckert Seamans to hear the results of its investigation; the firm, at the caucus’ request, sifted through a variety of allegations.

The Democratic caucus did not release that report Thursday, saying that senators had requested additional information and that a final version would be produced in the future.

Costa wrote that “Sen. Leach’s course of conduct created an unprofessional and sexualized environment. That should not be tolerated in any workplace; we will not tolerate it here."

On Thursday, Leach shot back, accusing Costa of saying “things he knows to be false.” In an interview, Leach accused Costa of caving to pressure from some inside the caucus, saying he had previously been told the report was final and would exonerate him.

“You don’t get to reopen a completed investigation because someone doesn’t like the result,” Leach said, adding later: “Essentially, this is a cover-up.” Costa said through a spokesperson that that was “preposterous.”

Leach said he believes that he is “the only member of the caucus not to have seen" the report. He said he had requested a copy and would not object if it were released.

Leach did see and release a 26-page PowerPoint presentation produced by Eckert Seamans, a document he said “absolved me of false charges made against me" — a notion the caucus disputed.

One slide that addresses Leach’s behavior in the office reads, “No evidence of actionable discrimination or harassment in violation of applicable law or Caucus policies; Senator Leach engaged in joking and humor that was immature and unprofessional; Jokes with a sexual context have the potential to create a hostile work environment.”

The presentation mentions nine sets of allegations, some of which were reported by The Inquirer in 2017. It says investigators reviewed thousands of pages of documents and interviewed 19 witnesses.

Costa announced in January that he had hired Eckert Seamans to investigate a complaint by Cara Taylor, an Allentown-area woman who alleges that Leach lured her into oral sex in 1991, when she was 17 and he was a lawyer representing her mother in a criminal case.

Leach has denied the allegation and filed a defamation suit against Taylor and activists who support her. In paperwork from that case, he called the 1991 incident “fictional.”

“Certain factual inconsistencies in Ms. Taylor’s recollection of events exist," one slide says. It also says she “steadfastly believed her account of what transpired — her testimony on this point was detailed and passionate.”

“Credibility disputes”can only be resolved in court, the slide said.

Among the newly public allegations raised was that Leach and a former employee watched a video clip that some people could describe as pornographic.

Leach, in the interview, said the employee showed him the video and one of his staff members “took corrective measures” when she heard about it.

“I wasn’t offended,” Leach said. “I probably should have been more direct about, ‘This is not the place.’”

The presentation also indicates that investigators looked at some allegations raised in an article published by The Inquirer. The story revealed that eight women and three men have claimed that Leach inappropriately touched female campaign staffers or subjected them to sexualized conversations. The presentation provides varying levels of detail about the firm’s findings on the allegations. Some, it says, did not rise to the lawyers’ definition of “actionable sexual harassment.”

In his statement, Leach acknowledged poor judgment.

“I have always felt that humor was a force for light in an often very dark world,” Leach wrote. “I apologize to anyone who may have been offended, and I will work hard to do better.”

Inquirer staff writer Angela Couloumbis contributed to this article.