WASHINGTON – As the House and Senate intelligence committees prepare for hearings with the whistleblower who complained about President Donald Trump’s dealings with Ukraine, the negotiations focused attention on how Congress protects anonymous witnesses.

The intelligence panels routinely hold closed meetings with unannounced witnesses. Other committees have accepted anonymous testimony about issues such as foreign affairs or drug use. In rare circumstances, steps to protect the witnesses included placing them behind screens and altering their voices electronically.

Those steps aren’t foolproof: An IRS whistleblower ran into her supervisor on the way to a hearing and blew her cover. The stakes are high for the Ukraine whistleblower, whose career relies on anonymity and who fears retaliation. Trump has said he’s trying to identify the person.

Andrew Bakaj, a former CIA officer who represents the whistleblower, tweeted Monday that the person “is entitled to anonymity. Law and policy support this and the individual is not to be retaliated against. Doing so is a violation of federal law.”

The whistleblower’s complaint is at the heart of the impeachment investigation of Trump at the House of Representatives. The complaint filed Aug. 12 alleged Trump abused the power of his office when he urged Ukraine's president to gather dirt on former Vice President Joe Biden, Trump's political rival. House Speaker Nancy Pelosi, D-Calif., announced a formal impeachment investigation based on news reports about the complaint.

The intelligence committees haven’t described how they will conduct the hearings. House Intelligence Chairman Adam Schiff, D-Calif., said the whistleblower’s lawyers need to obtain security clearances. Schiff voiced concerns on NBC’s "Meet the Press" on Sunday about congressional Republican contacts with the White House after Trump compared the sources who informed the whistleblower to spies.

“This is serious business here,” Schiff said. The panel is determining the logistics “to do everything humanly possible” to protect the whistleblower’s identity, which is “our paramount concern here,” he said.

The top Republican on the panel, Rep. Devin Nunes of California, said the whistleblower inquiry should have been handled behind closed doors without unending news releases promoting “fake news" that he called a “grotesque spectacle” and a “charade.”

The Senate Intelligence Committee treats whistleblower testimony the same as any confidential or secret information, meaning that a staffer would be fired for disclosing information without authorization. The director of national intelligence's general counsel has extended whistleblower protections to "disclosures made to the congressional intelligence committees," so long as the disclosures are made in a secure space.

Sen. Chuck Grassley, R-Iowa, a co-founder of the Senate Whistleblower Caucus, said the whistleblower deserves to be heard and protected.

“We should always work to respect whistleblowers’ requests for confidentiality,” Grassley said. “No one should be making judgments or pronouncements without hearing from the whistleblower first and carefully following up on the facts. Uninformed speculation wielded by politicians or media commentators as a partisan weapon is counterproductive and doesn’t serve the country.”

Anonymous witnesses

Closed hearings and anonymous witnesses are common before the intelligence panels. The House Intelligence Committee will have a closed hearing Friday with Michael Atkinson, the inspector general for the intelligence community, who deemed the whistleblower credible. As a rule, the Senate Intelligence Committee, which met in private with Atkinson last week, doesn’t announce the witnesses for its closed hearings.

Other panels have unnamed witnesses occasionally for sensitive subjects.

The Senate Foreign Relations and Armed Services committees had a closed briefing June 19 dealing with U.S. policy responses to Iran. Witnesses included Brian Hook, a State Department special representative for Iran; Kathryn Wheelbarger, a Defense Department acting assistant secretary for international security affairs; and an unnamed national intelligence officer for Iran.

The Senate Judiciary Committee held a hearing in Utah in July 2000 about emerging drug threats. The hearing featured an anonymous witness who testified about illegal drugs found at nightclubs and parties.

A Senate Foreign Relations subcommittee held a hearing in June 1997 about religious persecution that featured an anonymous witness from Pakistan. The Christian man told lawmakers that because of his religion, he was denied access to school, that police beat and jailed him and that he was detained at gunpoint.

Possible retaliation

An IRS hearing in September 1997 illustrated the risks facing whistleblowers who try to remain anonymous. The Senate Finance Committee held a hearing about IRS enforcement of tax laws. Six witnesses described as top IRS workers were granted anonymity and testified from behind screens, their voices modified electronically, to prevent their identification.

Whistleblower Jennifer Long, a 15-year IRS tax auditor, ran into her supervisor at a Houston airport where she was catching a flight to the hearing. Her cover blown, Long testified publicly at the nationally televised hearing about “egregious tactics used by IRS revenue agents.”

Long had received “fully successful” evaluations before her testimony, according to then-Finance Chairman William Roth, R-Del., then was given a warning of possible termination in April 1999, although she wasn’t fired.

“There is no question in my mind that Jennifer is being retaliated against for her testimony before the committee,” Roth said in a statement the day after Long got the warning.

Sanctions for revealing secrets

Whistleblower advocates said the people reporting alleged wrongdoing need to be protected from retaliation to avoid discouraging them from stepping forward.

“It’s a concern,” said John Kostyack, executive director of the National Whistleblower Center. “They would only do this hearing if the attorneys for the whistleblower believed that they had a reliable commitment on the part of everyone in the room to keep it confidential.”

Whistleblower advocates were encouraged about sanctions in cases involving the disclosure of confidential information.

James Wolfe, the former longtime director of security for the Senate Intelligence Committee, was sentenced to two months in prison in December 2018 after pleading guilty to lying to the FBI in an investigation of his contacts with reporters.

The investigation followed news reports about a Trump campaign adviser meeting with a Russian intelligence officer. Wolfe tearfully acknowledged at his sentencing that he lied to investigators, but he denied leaking classified information and was never charged with that.

In another case, John Fry, a former investigative analyst with the IRS, awaits sentencing Dec. 18 in federal court in San Francisco for leaking confidential government reports about suspicious transactions related to Michael Cohen, Trump’s former personal lawyer.

Fry pleaded guilty in August to unauthorized disclosure of suspicious-activity reports to Michael Avenatti in May 2018. Avenatti was the lawyer representing porn actress Stormy Daniels, who received a hush payment Cohen arranged from Trump before the 2016 election.