The U.S. District Judge expressed skepticism in hearing over a U.S. citizen's claim to immunity in a United Nations bribery scandal on Thursday. The judge seemed unimpressed because the U.S. citizen was working as a diplomat for a foreign government.

After hearing arguments by lawyers, the U.S. District Judge Vernon Broderick did not immediately rule on the fate of Francis Lorenzo, a U.S. citizen who was charged with being part of conspiracy included the bribery of a former president of the U.N. The Judge doubted that Lorenzo could be protected from prosecution of any crime because he was a deputy U.N. ambassador from the Dominican Republic, ABC News reported.

Francis Lorenzo, a now-suspended deputy U.N. ambassador, has been charged as a middleman in the U.N. bribery case. In October 2015, the federal prosecutors in Manhattan accused a former president of the U.N., John Ashe, of engaging a broad corruption scheme with a billionaire from the China. The bribery case involved more than $1 million in payments from sources in China for assistance in real estate deals and other business interests.

Beginning in 2012, Sheri Yan, who was a CEO of Global Sustainibility Foundation, was seeking to invest in Antiguan government officials or special favors that promoted their ventures in that country, CNN reported. Ashe was serving as Antigua and Barbuda's permanent representative at the U.N. He also served as the U.N. General Assembly's President from September 2013 to September 2014.

On Wednesday, the Chinese billionaire Sheri Yan, was ruled guilty in court of Manhattan with the bribery charges. Yan admitted that she agreed to pay money to Ashe to influence officials and the U.N. to support business interests, Reuters reported.

Earlier this week, a former finance director at the foundation, Heidi Hong Piao, was also pleaded guilty with the bribery charges and agreed to cooperate with authorities in their continuing investigation.

During the investigation, the prosecutors charged a billionaire real estate developerNg Lap Seng from Chinese territory of Macau for allegedly paying $500,000 in bribes to Ashe through intermediaries. Francis Lorenzo was one of the intermediaries.

Lorenzo has not pleaded guilty as prosecutors have said diplomatic immunity may preclude any bribery charges. But the prosecutors were examining the issue and likely would bring further charges.

In Thursday hearing, Assistant U.S. Attorney Rahul Mukhi said if Lorenzo's argument was supported by the law, then he could commit any crime and escape prosecution without facing the prospect of deportation since he is a U.S. citizen.

Mukhi said that no nation would agree with the diplomatic immunity scenario to escape prosecution.