A lawyer representing the unidentified whistleblower in Congress' impeachment investigation blasted "60 Minutes" on Sunday, saying the program "misinterpreted" a letter from his legal team in reporting that it indicated his client is under federal protection.

Mark Zaid, the attorney, tweeted that the famed news program "completely misinterpreted contents of our letter," which he linked to from his Twitter post.

The CBS program tweeted a brief defense of its report, saying: "60 Minutes stands by its sources and reporting on the whistleblower."

This prompted a more scathing response from Zaid.

"Is @60Minutes now asserting it has a source other than letter our legal team sent to @ODNIgov? Because if it doesn't, and I know it doesn't, then it is literally making stuff up. That helps no one, especially the #whistleblower. The media should always accurately report facts," he tweeted.

The whistleblower allegations represent a major threat to the Trump presidency. The allegation is that the president pressured Ukraine to investigate the Bidens, with some Democrats also arguing that he held up military aid as part of that effort. The whistleblower also claims that the administration went to great lengths to "bury" the controversial phone call on July 25 between Trump and Ukraine's President Volodymyr Zelensky.

Trump denies any wrongdoing and said he was just making sure that the country, known to be besieged by corruption, was getting off on the right foot with its new president.

"60 Minutes" reported Sunday that it received a letter that indicated that the government whistleblower has been put under federal protection due to safety concerns.

The report showed a PDF file of the Sept. 28 letter from the Compass Rose Legal Group, to the officer of acting Director of National Intelligence Joseph Maguire.

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The letter said, in part, "The purpose of this letter is to formally notify you of serious concerns we have regarding our client’s personal safety. We appreciate your office’s support thus far to activate appropriate resources to ensure their safety."

The letter did not specify the "support" or "resources" that were offered.

The letter stressed the urgency in protecting the whistleblower's identity and claimed that there's a $50,000 bounty for information about the client. The letter was signed by Andrew P. Bakaj, the lead attorney in the case.

"60 Minutes" did not immediately respond to an early morning email from Fox News.

One social media user highlighted the sentence in his legal group’s letter that expressed gratitude to Maguire’s office for activating the “appropriate resources to ensure” the whistleblower’s safety and asked what was misinterpreted.

An email to Zaid was not immediately returned.

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Zaid said talks are still ongoing and we “continue to work w/both parties in House & Senate & we understand all agree protecting whistleblower’s identity is paramount.” He said no time or date has been set.

Meanwhile, Fox News is told that the inspector general for the intelligence community who originally received the whistleblower complaint, Michael Atkinson, is scheduled to testify in closed session Friday before the House Intelligence Committee.

Fox News' Catherine Herridge contributed to this report.