BOSTON — Former Massachusetts Senate President Stan Rosenberg "failed to protect the Senate" from his husband, who has been charged with sexual misconduct, an ethics report released on Wednesday found, prompting calls for the lawmaker to resign.

The report prepared by independent investigators hired by the Senate Ethics Committee said that while Rosenberg did not violate any formal Senate rules, he showed a lack of judgment and violated the chamber's information technology policies by giving Bryon Hefner "unfettered access" to Rosenberg's Senate email account.

Republican Gov. Charlie Baker and Democratic Attorney General Maura Healey both called for Rosenberg, a Democrat, to resign following release of the report. A spokeswoman for Rosenberg said he would not be issuing any statements Wednesday evening.

Investigators said Hefner's access to Rosenberg's email began before he became president in 2015 and only ended in March 2017 after staffers detected two instances of Hefner surreptitiously emailing public officials as if he was Rosenberg.

Rosenberg "knew or should have known Hefner had racially and sexually harassed Senate employees" and failed to address the issue adequately, the report said.

Rosenberg stepped down as Senate leader in December but remains in the chamber and has indicated he plans to run for re-election in his western Massachusetts district. The ethics committee recommended that Rosenberg not be allowed to serve in any leadership position or as a committee chair at least through 2020.

Hefner, 30, pleaded not guilty in Suffolk Superior Court last month to charges of sexual assault, criminal lewdness and distributing nude photos without consent. He was released on personal recognizance and his attorney has said he would defend himself in court.

Rosenberg announced earlier this year that he and Hefner had separated.

"The special investigator's conclusions — which do not establish a violation of any formal Senate rule — nonetheless demonstrate a significant failure of judgment and leadership by Senator Rosenberg in his role as Senate President," the report stated. "That failure undermined the integrity of the Senate and had destructive consequences for the Senate and the people with business before it."

"Essentially, Senator Rosenberg failed to protect the Senate from his husband, whom he knew was disruptive, volatile and abusive," investigators concluded.

The report revealed a "deeply disturbing" pattern of behavior, Baker said in a statement.

"For the good of the institution and those who elected him to serve, I believe the Senator needs to resign immediately," the governor said.

Healey, whose office brought the charges against Hefner, also called on Rosenberg to resign as did the state's Republican party. Democratic leaders in the Senate stopped short of calling on Rosenberg to quit, but current Senate President Harriette Chandler termed the report "thorough and troubling."

Senators did not rule out the possibility of further sanctions — such as a formal reprimand or censure — as they continue to review the report in coming days.

In 2014, before his election to the top post in the Senate, Rosenberg assured colleagues he would build a "firewall" between his professional and personal life, following reports that Hefner had boasted on social media about his influence with Rosenberg.

But that firewall was "ineffective," the report said.

According to investigators, Rosenberg was aware Hefner "routinely expressed in graphic terms sexual interest in members of the Senate and Senate staff," and was also aware that his husband had downloaded and texted images of nude men. In another incident, the report said, Hefner used racial epithets against a Senate staffer, and Rosenberg told the staffer to inform Senate counsel.

But investigators said there was no evidence the senator knew of any alleged criminal behavior by his husband.

Rosenberg, 68, was the first openly gay lawmaker to lead a legislative chamber in Massachusetts.