The top Republican in the Senate is urging the Yuan to learn the details of its handling of sexual harassment allegations.

R-IOWA Senate Justice Chairman Chuck Grassley sent a letter to the company on Tuesday asking about allegations published in March, and its executive Joel Kaplan sent employees sexually harassment emails in 2015 and 2016. The letter also asked about other substantive training on harassment or work materials to seek other substantive allegations of “competition” for training and “competition” since 2010.

Meta responded to Grassley via letter late Tuesday and said it planned to hand over an internal report that Kaplan cleared wrongdoing in 2017, according to the company.

Heidi Swartz, vice president of employment law and investigations at Meta, also provided a meeting with Grassley staff in the letter.

Grassley's review of the matter appears to be in an early stage, part of a broader question that the Senators have been asking the Meta-man how to comply with federal laws that protect whistleblowers.

Grassley’s problem is part of the impact of former Facebook employee Sarah Wynn-Williams’ best-selling memoir The Careless Man. The book chronicles her more than six years of international affairs for the social media giant, a work that has brought her direct contact with CEO Mark Zuckerberg and other C-Suite executives.

In the book, lawyer and former New Zealand diplomat Wynn-Williams blames the company for subverting politics in the United States and elsewhere. She also filed charges against her boss Kaplan, writing that she faced retaliation and was fired in 2017 after reporting Kaplan’s report internally.

A Grassley spokesman said in a statement to NBC News on Wednesday that the senators are "reviewing the allegations filed by Wynn Williams to determine its authenticity" and is reviewing Mehta's response.

"The cooperation between Yuan and Wynn Williams is essential as his office is committed to identifying the factual pattern of Wynn-Williams' allegations," the spokesperson said.

Meta delayed Wynn-Williams' charges, saying she was fired for performance reasons and was unreliable.

“Ms. Wynn Williams filed the charges only after she made it clear that her ongoing and well-documented performance issues were no longer ignored,” Meta’s attorney Swartz wrote in a response to Grasley.

"Ms. Wynn-Williams is the only person who made such a charge against Mr. Kaplan during his 14 years at the company," Swartz added, accusing Wynn-Williams of being a "inciteer" of color jokes during her time at the company.

In March, Meta won an arbitration order saying Wynn-Williams violated a non-term of service in her severance agreement. This prevented her from getting promoted, but couldn’t release her memoir, which has listed the best-selling non-fiction list in The New York Times.

Grassley, whose Senate advocacy for whistleblower protection has been long, expressed concern that Meta would consider Wynn-Williams as whistleblower. Last month, he was worried that Meta would “bully” Wynn-Williams would remain silent. Meta said there were no restrictions on Wynn-Williams talking to investigators.

Wynn-Williams testified before the Senate Judicial Subcommittee last month, lawmakers on both sides expressed deep anger at the company's various subjects. Many senators focused on the company's pursuit of breaking into the Chinese market over the years, where Facebook and Instagram of its apps were banned and privacy jeopardized Meta, before thinking about it before giving up on the job in 2019.

Wynn-Williams welcomes Grassley's inquiry, said Ravi Naik, a lawyer for Wynn-Williams.

“My clients appreciate Chairman Grassley and his Senate colleagues’ graveness of the issues being investigated,” Naike said in a statement. “While Meta and Mark Zuckerberg claim to be free speech champions, they continue to silence my clients, a whistleblower who moves forward to report wrongdoing and illegal activities that threaten the safety of its users, national security and employees.”

In Grassley's letter to Meta, he quoted three emails from Kaplan to Wynn-Williams, with three of which also quoted Wynn-Williams in her memoirs. Kaplan asked her U.S. citizen test in a 2016 whether the term “dirty Sanchez” was included, a sexual lang language and racial slander. In his second email in 2015, after Kaplan received funding for a new position on her team, he emailed: "Who is your sugar daddy?" In a third of 2015, he promised that if she met a budget goal, he would "buy 'something nice' for you in person ("Byers/Buyers").

"I have made very serious allegations of revenge and sexual misconduct by the whistleblower," Grassley wrote.

Kaplan is Wynn-Williams' boss and vice president of global public policy when sending an email. Wynn-Williams wrote in her memoir that she thought the 2015 email was “very mild”, but the “dirty Sanchez” problem was “new lows”, “totally inappropriate” and showed that his behavior was “becoming worse and worse.”

In January, Zuckerberg promoted Kaplan to chief global affairs officer, making him the head of all the company's lobbying activities. Her allegations were made public in March when Wynn-Williams spoke about the allegations in an interview with NBC News before her memoir was published.

Meta did not give the accuracy of the email or comments on its content. Kaplan also did not comment on the allegations, nor did it respond to an email request for Grassley's letter. Some current and former META employees, including women, have active experience working with Kaplan.

Yuan’s attorney Swatts wrote Tuesday that the internal investigation into Kaplan did not cover his email because she wrote that Wynn-Williams did not file an email during the investigation. Swartz wrote that she believed Wynn-Williams did not make an email at the time because she knew she was usually an agitator and had a record of making color jokes and did not want to prompt an investigation into her behavior. ”

In her memoir, Wynn-Williams describes the investigation in a different way. She wrote that Meta quickly ended his internal review of Kaplan, “before receiving or reviewing all the documents and information I said I would provide.”

"Emails and documents speak for themselves. My client took the oath to testify about this harassment in the Senate and will continue to stick to the facts," Naik, attorney for Wynn-Williams, said in a statement.