AUSTIN — After the conclusion of a sexual harassment investigation into Sen. Charles Schwertner, the Georgetown Republican has requested he be relieved of his chairmanship duties for the powerful Health and Human Services Committee.

According to a letter obtained by The Texas Tribune, Schwertner asked Lt. Gov. Dan Patrick not to reappoint him as chairman.

"Per our discussions, I have asked not to serve in that capacity this session so that I can work and lead on other policy issues for my district as well as spend more time with my family," he wrote in a letter dated Friday.

Patrick said via email that he was planning to strip Schwertner of the leadership position.

"I can confirm that Senator Schwertner's request is consistent with what I was already planning for the upcoming session," he said.

On Dec. 18, the University of Texas at Austin released a summary of its investigation into allegations that Schwertner sent lewd messages, including pictures of genitals, to a UT student. The investigation said it could not conclusively determine that Schwertner sent the messages.

But the investigation also did not fully exonerate him. It described him as uncooperative and left open the possibility that he was lying. It also found that the messages to the student came from both his LinkedIn and Hushed accounts, but not his cellphone. Hushed is a smartphone app that lets people disguise their numbers.

The investigator reported that Schwertner said the messages were sent by an unidentified person to whom he had given his passwords. But Schwertner told the investigator he would not reveal the person's identity.

After the investigation was closed, Schwertner and his attorneys released statements saying he had been vindicated. They have not responded to repeated messages seeking additional information, including why he will not reveal the person's name.

When the Austin American-Statesman first reported the allegations in September, Patrick said he was "deeply concerned" but was awaiting the conclusion of the university investigation.

Asked if had concerns about the results, Patrick said, "I can say we do not know the identity of the complainant and, at this time, no complaint has been filed."

Williamson County Republican Party precinct chairman Jason Vaughn, who said he has block-walked for Schwertner's campaign, said he is baffled and disappointed by the senator's explanation.

"The senator says he does not support harassment but has refused to reveal who this third party is and thereby is flagrantly enabling harassment," Vaughn said. "This is a mark upon the Texas Senate and the Republican Party."

"Protecting sexual harassers is not acceptable," he added.