The anonymous whistleblower who has accused President Donald Trump of pressuring Ukraine's president to investigate former Vice President Joe Biden is not paying a dime for a high-quality team of lawyers who specialize in government-whistleblower cases.

The team of attorneys are working pro bono, which means the client won't have to cover their fees.

"It was the right thing to do," said one of the lawyers, Mark Zaid, managing partner in Mark S. Zaid in Washington, D.C., who's working alongside Andrew Bakaj and Charles "Chuck" McCullough, both of Compass Rose Legal Group.

Zaid added that the team will get compensation from Whistleblower Aid, a nonprofit that raises funds to assist whistleblowers with legal costs and other expenses. Whistleblower Aid has launched a GoFundMe campaign that raised nearly $138,000 in the past couple of days to pay the whistleblower's legal costs.

"One of our key objectives now is to ensure the anonymity of the whistleblower," Zaid said, noting he hopes the source's identity never comes out, even if the person testifies before Congress about the complaint.

Zaid said it's vitally important for government whistleblowers who disclose misconduct or abuse dealing with national security information to follow the proper procedures to file a whistleblower complaint, because otherwise, they face criminal liability.

For example, leaking classified information to the news media has landed past whistleblowers such as Reality Winner and Chelsea Manning in federal prison.

"The key, especially in the national security world, is to make sure the person dots their i's and crosses their t's so there is no mistake made that would enable the government to reprise against the individual because they lack protection," Zaid said.

He said he doesn't expect the whistleblower to face any criminal troubles because the person followed the law to disclose the claim about Trump.

Even if the threat of criminal prosecution is absent here, whistleblowers often face consequences at work or home after they make their disclosures. They often face retaliation at work, which can be lessened if they're willing to leave that job.

"I'm always fearful for any of my whistleblower clients, but if they follow the law and the whistleblower is hopefully represented by a lawyer who is well-connected, then we have a better chance to protect them," Zaid said.

He said he's worked with many high-profile whistleblowers, but none who raised claims against a president.

When asked if this is his biggest whistleblower case so far, Zaid replied, "By way of potential impact, I can't imagine how to say no to that."