One of the most lucrative private banks in Myanmar has hired a legal powerhouse after its holding company was implicated in a scathing United Nations report that blasted the country's military.

Kanbawza Bank has tapped Williams & Connolly, a U.S.-based law firm, to be the company's legal representatives in case U.S. sanctions arise from the U.N.'s fact finding mission. The report accuses Myanmar's military of having ties to a litany of businesses and that those dealings have led to extensive human rights abuses. The U.N. called for a criminal investigation into KBZ Bank's parent company, KBZ Group, for allegedly funding a border fence that has prevented Rohingya Muslims from returning to Myanmar after fleeing the country in 2017.

The firm sent a letter to the bank's CEO, Michael DeNoma, earlier this month and it describes the agreement between the two parties, including a $250,000 retainer.

"Williams & Connolly LLP will provide legal services to you in connection with potential US legal issues and sanctions matters which may arise out of an August 5, 2019 UN Human Rights Council Report on Myanmar," David Aufhauser, a partner in the firm, wrote. Aufhauser was previously a managing director and global general counsel at investment bank UBS.

The bank's new hire was discovered after CNBC reviewed foreign lobbying registration forms, with one of the documents describing other responsibilities that may involve having to reach out to members of President Donald Trump's administration, congressional lawmakers and the U.N. itself.

"Additional services will potentially include providing advice regarding legal consequences of the report, providing advice on lobbying and public relations issues related to the representation, lobbying U.S. government officials in the Executive Branch, Congress,and/or the United Nations, and discussing the matter with U.S. or international media organizations," the exhibit reads.

The U.N., Aufhauser and KBZ Bank did not return requests for comment.

The effort by KBZ Bank to retain a marquee legal team suggests there are internals fears of severe backlash after the U.N. report, especially from foreign governments such as the U.S. The bank itself has always been held in a high regard around the world.

The Milken Institute, a economic think tank based out of California, described KBZ Bank in a 2017 study as a firm that dominates the Myanmar market.

"Among the privately owned banks, the so-called 'Big Three' dominate the market," the study says. "Combined, Kanbawza Bank (KBZ), Ayeyarwady Bank (AYA), and Co-operative Bank (CB) control about two-thirds of all loans, two-thirds of all deposits, and more than 50 percent of all bank branches in the country."

Members of the U.N. are scheduled to meet in September for the 74th session of the General Assembly in New York.