FRANKFORT, Ky. — An investigation into a secret sexual harassment settlement involving four Republican lawmakers in Kentucky will be delayed because some current and former GOP staff members are refusing to cooperate.

The Courier Journal first reported the settlement amid a national uproar over sexual misconduct by powerful men in media, politics and entertainment. After initially backing the former House speaker, Republican legislative leaders announced they would hire a private law firm to investigate.

That firm, Louisville-based Middleton Reutlinger, was supposed to release its initial report Wednesday. Instead, acting House Speaker David Osborne announced he was extending the deadline to Dec. 1 after lawyers said they needed more time to convince some uncooperative witnesses to talk to them.

“I understand that procedural hurdles a lack of cooperation by at least two people have hindered progress,” Osborne said in a news release. “I am very disappointed in the procedural delays the investigators experienced and will be addressing these issues in the days ahead.”

Former House Speaker Jeff Hoover resigned his leadership position earlier this month after acknowledging he paid an undisclosed amount to settle a sexual harassment claim brought by a member of his staff. Hoover denied sexually harassing the person, but said he sent inappropriate but consensual text messages.

While Hoover resigned, he remains in the state legislature. Three other lawmakers were also involved in the settlement. They have lost their committee chairmanships, but have not resigned their seats.

Rep. Brian Linder of Dry Ridge has publicly apologized for his actions. Rep. Jim DeCesare of Bowling Green has declined to comment, but told a Bowling Green TV station he has “done nothing to be ashamed of.” Rep. Michael Meredith of Oakland has not commented on the allegations.

Osborne said legislative leaders are still considering handing off the investigation to another agency that would have the power to subpoena witnesses. House Democratic Leader Rocky Adkins has urged lawmakers to call a meeting of the bipartisan Legislative Research Commission, which would have the power to issue a subpoena.

But the Legislative Research Commission consists of 16 lawmakers, meaning the legislature would be investigating itself. Another option is the Legislative Ethics Commission, an independent agency whose members are appointed by legislative leaders to set terms. Democratic Rep. Jim Wayne of Louisville has already filed a complaint with the agency, the first step to a formal investigation.

The agency must first conduct a preliminary investigation in secret. It would not become public unless the commission believes there is probable cause the lawmakers violated state ethics laws.

The commission last handled a public sexual harassment investigation in 2014, when it fined a former Democratic lawmaker $3,000 for inappropriately touching some female legislative staff members. That lawmaker, John Arnold, resigned from office after the allegations became public.