AP 11:34 p.m. EDT September 24, 2015

A gavel sits on a desk.(Photo: Brennan Linsley, AP)

NEW YORK (AP) — One of the world's wealthiest people — a Chinese real estate mogul at the center of a Democratic campaign fundraising scandal two decades ago — has been grounded from his fleet of private planes and stripped of his $200,000 watch after his incarceration without bail in Manhattan as U.S. investigators probe where his money goes.

Federal authorities have charged Ng Lap Seng, 68, with lying about his plans for $4.5 million in cash he brought into the U.S. over several years aboard private jets. They say they followed him enough to know he wasn't spending the cash at casinos, on art and antiques or on real estate, despite his claims to the contrary.

His lawyer, Kevin Tung, has argued that a criminal complaint charging Ng with conspiring to obstruct and making false statements to the U.S. Customs and Border Protection agency is based on a misunderstanding.

"If you look at this complaint on its face, people carrying money in or out without filling out a form, maybe in violation of something, but this is not really a crime," he said. "The United States tries to portray this man as a very, very rich man. But I don't think that has any relevance here."

He added: "People do not know when they're coming to this country if they carry some cash, there might be a problem."

In 1998, a Senate committee reported Ng sent over $1.1 million to a one-time Little Rock, Arkansas, restaurant owner, who contributed hundreds of thousands of dollars to the Democratic National Committee and later pleaded guilty to a felony. Ng visited the White House 10 times from 1994 to 1996 and had his photograph taken with President Bill Clinton and first lady Hillary Rodham Clinton.

Incarcerated since Saturday, Ng failed to convince a magistrate judge Monday that he would return to court if released. According to court papers, Ng heads a major real estate development company in Macau, China.

U.S. Magistrate Judge Sarah Netburn rejected a request that Ng be released on bail secured by his $3.8 million Manhattan apartment and electronic monitoring.

"Obviously, being wealthy is not in and of itself, a crime, and I don't think anybody is accusing your client of criminal activity merely because of his wealth," she said.

The judge commented after Assistant U.S. Attorney Janis Echenberg made Ng's wealth a focal point of her argument against bail.

Echenberg said Ng had reported a net worth of $1.8 billion, including $300 million in annual earnings, $1 billion in Chinese real estate, a $30 million fleet of private jets and a gold watch with diamonds that had been estimated to be worth $200,000.

The prosecutor said Ng, who has passports from China, Portugal and the Dominican Republic, was also a flight risk because he has access to $20 million in U.S. currency that he has wired into the country, "tremendous international ties without any real ties to the United States" and he stopped coming to the United States between 1996 and 2000 when Congress was looking into the fundraising scandal.

According to court papers, Ng was also served in July 2014 with a subpoena to appear Sept. 17, 2014, in connection with an unrelated investigation. But he did not show up.

Ng's chief assistant, Jeff C. Yin, was arrested on the same charges Saturday. He also remained incarcerated Thursday, though he may be freed soon on $1 million bail.

At a bail hearing Saturday, Assistant U.S. Attorney Daniel Richenthal described Yin, a U.S. citizen, as Ng's right-hand man in his U.S. operations, someone who played a key role in transmitting funds.

The prosecutor said Yin spoke to law enforcement after his Saturday arrest, admitting he transmitted money on Ng's behalf to pay people to do unlawful things, though Yin interrupted the prosecutor, saying: "That is not true," according to a hearing transcript.

Federal Defender Sabrina Shroff, representing Yin, said at the hearing that her client, educated in the United States with family here, may have served as Ng's "mouthpiece" but the cash and the investments were not Yin's.

"He doesn't know what Mr. Seng is doing with the money at the end of the day," Shroff said.

Shroff said a government agent told her Yin "holds his boss in high regard and doesn't think his boss did anything wrong."

Tung said in an email Thursday that he might try again to get his client released on bail.

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