Updated

A Ukrainian man accused of operating one of the most extensive child porn distribution networks ever prosecuted in the U.S. pleaded not guilty Wednesday in federal court.

A court-appointed attorney entered the plea on Maksym Shynkarenko's behalf Wednesday in U.S. District Court in Newark. The Ukrainian government says he is innocent, and his mother says his arrest is a case of mistaken identity.

The 33-year-old from Kharkiv has been charged with 32 counts for allegedly operating Ukraine-based hardcore child porn sites with three co-conspirators who have not been named — two from the Ukraine and one from Russia — according to court documents.

Prosecutors say Shynkarenko sold access to the sites to clients worldwide, listing the charges under innocuous names to elude detection by credit card companies, but warning customers to lie and say their credit cards had been stolen if questioned by police.

He was extradited to the U.S. from Thailand this week. He was charged in New Jersey because the case began when agents from U.S. Immigration and Customs Enforcement's investigative arm first discovered a website allegedly run by Shynkarenko on the computer of a New Jersey customer in 2005.

The U.S. attorney for New Jersey, Paul Fishman, said 560 U.S.-based customers from 47 states have been convicted so far. Prosecutors said 10 to 50 customers a day were attempting to access sites allegedly run by Shynkarenko with names including "Illegal.CP," ''The Sick Child Room," ''Hottest Childporn Garden," and "Pedo Heaven," before they were shut down in 2008.

Shynkarenko was arrested in Thailand in 2009 while on vacation, and had been fighting extradition to the U.S. since.

Ukraine Foreign Ministry spokesman Oleksandr Dikusarov told The Associated Press on Tuesday that local investigators had found no evidence of Shynkarenko committing a crime, and they would work to defend him.

Tetyana Cherenok, Shynkarenko's mother and a 64-year-old retired engineer, told the AP this week that her son is innocent and had been mistaken for another man with the same first and last name.

The court-appointed federal public defender for Shynkarenko, Linda Foster, declined to comment on his behalf Wednesday. Shynkarenko, in shackles and wearing dark green prison scrubs, did not speaking during the brief proceeding. Foster did not request bail for him, and he remains in custody.

He could face up to life in prison if convicted on all counts.

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