UNITED NATIONS — A U.N. document translator, Vyacheslav Manokhin, was arrested yesterday on charges that he allegedly helped citizens of two former Sovietstates illegally obtain American entry visas by claiming they would participate in U.N. events, such as one titled “International Symposium Changing Boundaries: Architectural History.”

International conferences with such seemingly nonsensical titles regularly take place at the United Nations and its affiliates. But the conferences mentioned in yesterday’s criminal complaint in U.S. District Court in Manhattan were allegedly even less noteworthy: Allegedly, some were entirely made up, while others took place only as covers for illegally smuggling foreign nationals into America or France in exchange for payments of up to $15,000 a head.

Mr. Manokhin was part of “a sophisticated global network” that “is very good at what it does,” an assistant U.S. attorney, Michael Farbiarz, said at a bail hearing before U.S. Magistrate Kevin Fox yesterday.

Judge Fox ordered that Mr. Manokhin, a resident of Greenwich, Conn., be released prior to trial on a $300,000 bond, $10,000 of it in cash. All travel documents belonging to Mr. Manokhin, a Russian national, were surrendered, and his movement was restricted to New York and Connecticut.

According to the complaint, issued yesterday by the office of the U.S. attorney for the Southern District of New York, Mr. Manokhin is charged with using his office at U.N. headquarters to vouch for six citizens of Ukraine and 15 citizens of Uzbekistan who were said to be joining U.N.-sponsored conferences in New York or Paris. He is also accused of writing letters on several U.N. letterheads on which he allegedly signed aliases such as “Leonardo Brackett” or “Greg Smith.”

The complaint alleges that rather than attending the events, the visa seekers would disappear into the woodwork, opting for such destinations as Miami instead of New York, where the allegedly conferences were to take place. In at least two of the cases, which allegedly took place over two years, the entrants paid $15,000 apiece for the setup, according to the complaint.

“I personally met the representatives of this organization during my visit to Kazakhstan. I believe that their participation in this event will be very meaningful,” Mr. Manokhin is alleged to have written in a July 5, 2005, letter on U.N. Development Program letterhead over the signature “Leonardo Brackett, Project Manager.” The letter was attached to yesterday’s complaint as an example to how the alleged operation worked. The only problem, the complaint charges, is that no “Brackett” — or a “Greg Smith” for that matter — exists in databases of U.N. employees. Mr. Manokhin allegedly listed his own U.N. telephone number so that, when contacted to confirm details in such letters, he could pretend to be an assistant to “Mr. Brackett” and vouch for the authenticity of the documents.

An immigration attorney’s aide, Vladimir Derevianko of New Jersey, was charged with devising the plan along with Mr. Manokhin. Mr. Derevianko was also arrested yesterday and released on a $250,000 bond. A third defendant, Kamiljan Tursunov of Uzbekistan, was allegedly one of the visa applicants who paid $15,000 for the scam. He was arrested in Miami last month.

“These men are good at manipulating the system and getting phony and false documents,” Mr. Farbiarz said at yesterday’s hearing, as he argued against freeing them on bail. “They are pros.”

An attorney for Mr. Manokhin, Robert Sikorski, declined comment; Mr. Manokhin was represented by a court-appointed attorney, Alex Oh.

A U.N. spokesman, Farhan Haq, said yesterday that on July 27, the organization had stripped Mr. Manokhin of his immunity from prosecution. While not initiating the case, the internal watchdog at the United Nations, the Office of Internal Oversight Services, helped the U.S. attorney in the investigation, he added.

“As of right now, he is not suspended,” Mr. Haq said when asked about Mr. Manokhin’s employment status.