CNN suspended prime-time anchor Chris Cuomo indefinitely after records released this week by the New York attorney general’s office provided a detailed look into his efforts to help his brother, former New York Gov. Andrew Cuomo, respond to allegations of sexual misconduct.

In a statement released Tuesday, CNN said that the records “raise serious questions” about Chris Cuomo’s conduct. “These documents point to a greater level of involvement in his brother’s efforts than we previously knew,” a CNN spokesman said. “As a result,...

CNN suspended prime-time anchor Chris Cuomo indefinitely after records released this week by the New York attorney general’s office provided a detailed look into his efforts to help his brother, former New York Gov. Andrew Cuomo, respond to allegations of sexual misconduct.

In a statement released Tuesday, CNN said that the records “raise serious questions” about Chris Cuomo’s conduct. “These documents point to a greater level of involvement in his brother’s efforts than we previously knew,” a CNN spokesman said. “As a result, we have suspended Chris indefinitely, pending further evaluation.”

The records, which were released Monday, include transcripts and exhibits from an investigation into allegations of sexual harassment against Andrew Cuomo. They show Chris Cuomo gave detailed feedback on his brother’s statements to the press and gathered information about coming stories involving his brother’s accusers.

In lieu of Mr. Cuomo, CNN anchor Anderson Cooper will host an additional hour this evening, according to a person familiar with the matter.

The records include text messages sent by Chris Cuomo to one of his brother’s top aides and a transcript of an interview with Chris Cuomo conducted by investigators working for New York Attorney General Letitia James.

Mr. Cuomo didn’t immediately respond to a request for comment.

Mr. Cuomo is one of CNN’s biggest stars, anchoring the network’s 9 p.m. hour in prime time. His suspension comes as CNN’s parent company, AT&T Inc., is preparing to merge its media assets with those owned by Discovery Inc.

Discovery Chief Executive David Zaslav gathered with CNN President Jeff Zucker and his top lieutenants at the network’s Hudson Yards headquarters on Tuesday afternoon as part of a series of corporate pre-scheduled meet-and-greets that the two companies held since the deal was announced, according to people familiar with the matter. Mr. Cuomo’s fate at the network wasn’t discussed at the meeting, one of the people said.

As of late afternoon Tuesday, several top producers at the network were unaware that Mr. Cuomo wouldn’t be anchoring his show, according to people close to the network. Mr. Zucker delivered the news to Mr. Cuomo directly during a meeting Tuesday afternoon, according to a person familiar with the matter.

Andrew Cuomo stepped down as governor of New York earlier this year after a report by Ms. James’s office that said he sexually harassed multiple women in violation of state and federal laws, created a hostile work environment and retaliated against at least one former employee. Andrew Cuomo has said he never touched anybody inappropriately.

After Ms. James’s office released new records on Monday, a spokesman for Andrew Cuomo said that aspects of Ms. James’s investigation into the former governor were politically motivated.

The newly released records provided the most detailed look to date of Chris Cuomo’s attempts to guide his brother, including an interview with investigators where the CNN anchor said he reached out to sources—including other journalists—to figure out whether additional complaints of sexual misconduct against his brother might surface.

Chris Cuomo said during the interview with investigators that he didn’t conduct opposition research on the women who accused his brother of misconduct and said he made inquiries only at the request of his brother’s advisers.

The records include text messages between Chris Cuomo and Melissa DeRosa, who was then one of his brother’s top aides. Chris Cuomo suggests possible statements to the press in the aftermath of stories about sexual misconduct involving Andrew Cuomo, at one point annotating his brother’s response in detail. In another text, Chris Cuomo told Ms. DeRosa that he had information.

“I have a lead on the wedding girl,” Chris Cuomo texted Ms. DeRosa on March 4. The text came days after the New York Times published an article that included an interview from a woman who accused Andrew Cuomo of inappropriate touching at a 2019 wedding reception. It couldn’t be learned whether Chris Cuomo’s text referred to that article.

In May, after details of Chris Cuomo’s efforts to help his brother first surfaced, Mr. Zucker, the president of CNN, said in an employee meeting that the anchor had “made a mistake” by participating in strategy sessions with his brother, but said he didn’t see a point in suspending Chris Cuomo, adding that taking him off the air would amount to “punishment for the sake of punishing.”

Chris Cuomo joined CNN in 2013 from Walt Disney Co. ’s ABC News. After co-anchoring the network’s morning show, “New Day,” he moved to a prime-time slot in 2018.

In September, Chris Cuomo was accused of groping a TV journalist at a party in 2005 when they were co-workers at ABC News. He responded by saying he regretted the incident, which he said wasn’t sexual in nature. CNN had no additional comment at the time.

Write to Benjamin Mullin at Benjamin.Mullin@wsj.com