FARGO - A federal appeals court has upheld the sentence of man convicted in a human smuggling case in which authorities said thousands of illegal immigrants were brought to work at restaurants at North Dakota and other states.

Shan Wei Yu, of McKinney, Texas, is serving nine years for illegal immigrant trafficking and money laundering. He appealed on six issues, including a claim that his sentence was unusual.

A three-judge panel of the 8th U.S. Circuit Court of Appeals denied the appeal Wednesday, saying U.S. District Judge Ralph Erickson "gave weight to all the relevant factors" in handing down the sentence.

"There were an enormous number of illegal aliens involved in this smuggling scheme," Assistant U.S. Attorney Nick Chase said.

"Yu essentially had a two for one policy," Chase said Wednesday. "If any of his workers would leave or not work out, he would deliver another one for free. I just think you're getting so close to treating people like commodities or a product."

Authorities said they began investigating Yu in 2004, after a border patrol agent found two men riding bicycles on Interstate 29 in North Dakota.

They admitted they were illegal immigrants from Mexico who were working at a Grand Forks restaurant, and one had an employment contract saying he would be paid $1,000 per month, court records said.

Erickson said in court that the scheme amounted to slave labor and that Yu was dealing in a "human tragedy."

Chase said it was the first time he asked for a sentence on the high end of federal guidelines. He had asked for the maximum of 10 years, which Erickson said he would have approved except for Yu's poor health, according to court documents.

Authorities said during the trial that Yu and his company, Great Texas Employment Agency, brought at least 1,000 illegal immigrants into the United States. Chase said that number was likely much higher.

"At trial, he said he delivered over 6,000 aliens to different restaurants and he claimed all of them were legal," Chase said. "That flew in the face of the facts."

Authorities believe Yu earned at least $900,000 for the workers he placed at restaurants across the country. He hired drivers to deliver at least 40 illegal immigrants to Asian restaurants in North Dakota during a 15-month stretch, prosecutors said.

Yu's girlfriend, Ya Cao, was sentenced to 21 months in prison for helping recruit illegal workers. Cao's attorney, Lee Finstad, said Yu took advantage of Cao after she came to the U.S. to seek political asylum.

The appeals court denied Yu's claim that he should have been granted a competency hearing to assess whether he was able to understand the proceedings and assist his trial lawyer. Yu defended himself during much of the case.

"I never saw anything that suggested to me that he wasn't competent and neither did his trial counsel, who never raised the issue," Chase said. "It was never much of an issue in my mind."