A Chinese billionaire arrested in a United Nations bribery scandal asserted in court papers Thursday that charges against him were politically motivated, a way for the United States to block his construction of a major U.N. conference center in China and slow the progress of Chinese influence over developing nations.

Lawyers for Ng Lap Seng said in papers filed in Manhattan federal court that charges brought against the 68-year-old businessman last fall were based on a "fundamentally unsound" and unprecedented criminal prosecution.

They said the charges had derailed any plans for a permanent conference center in Macau that would serve southern hemisphere nations.

"There is every reason to believe that the U.N. has, indeed, completely shelved the idea of such a center. The U.S. geopolitical interest in slowing the progress of Chinese influence over developing nations has been achieved," the lawyers wrote.

Ng is free on $50 million bail with a requirement he be guarded by around-the-clock private security at a luxury Manhattan apartment.

Prosecutors say he contributed a portion of over $1 million in bribes to a former U.N. General Assembly president to generate support for his plans for a U.N. conference center in Macau.

But his lawyers say his prosecution was designed to prevent the establishment of the Macau center. They note that his arrest came within three days of a scheduled state visit by the Chinese president to the United States.

They also argued in the court papers Thursday that the United States was improperly interfering with the customs and operations of the United Nations.

"Not only has the prosecution intruded into U.N. affairs, it threatens to import American sensibilities and customs into a uniquely international environment that has its own set of customs and expectations," the lawyers said.

As part of their court submission, the lawyers submitted a transcript of an interview the FBI conducted with Ng after his arrest.

In it, Ng was asked about a photograph on the internet of him with President Barack Obama.

According to the transcript, Ng said he was introduced to Obama by a friend from Taiwan.

Ng also said in the transcript that his primary reason for trips to the United Nation was to promote the construction of the U.N. center in Macau.

"My goal is to build this exhibition center, the largest in the world," Ng is quoted as saying.

A spokesman for U.S. prosecutors declined comment Thursday.