Mogilyansky, a dual citizen, was charged last week with traveling to orphanages in his native country to molest young girls and hire them out as prostitutes. He denies the allegations.
At a detention hearing Wednesday, prosecutors contended Mogilyansky has the means to flee, including money and property abroad.
But defense attorney George Newman said his client has pledged all his assets as securities for his release. He also noted Mogilyansky - who is married with three children - has known about the U.S. investigation for a few years and has not fled, though he had ample opportunity.
Mogilyansky has already posted $50,000 cash bail and surrendered both passports, and 12 people have pledged their homes as collateral, Newman said.
"He's not going to leave all these people holding the bag," Newman said. "He wants to face the charges."
Assistant U.S. Attorney Michelle Morgan-Kelly said the money posted by Mogilyansky is "a mere pittance to this defendant." Mogilyansky, who owns several businesses, estimated his personal fortune at $5.3 million in 2006.
However, Newman said a couple of his client's companies now have no significant assets, and Mogilyansky's car-export business is facing hardship because of the economic decline.
U.S. Magistrate Carol Sandra Moore Wells ruled that Mogilyansky must post another $50,000 cash bail in order to be released under house arrest, with electronic monitoring, computer monitoring and other restrictions. She stayed her ruling pending prosecutors' appeal.
Wells said one factor in her decision to release Mogilyansky was that the alleged crimes took place five years ago. There has been no recent evidence to indicate Mogilyansky would be a danger to the community, she said.
Morgan-Kelly argued that Mogilyansky could be a flight risk because he owns apartments in Russia and Ukraine. But Newman said those are occupied, adding that Mogilyansky would not travel to Russia because of a pending criminal investigation. And Ukraine has an extradition treaty with Russia, Newman said.
Four Russian men already have been convicted in that country in connection with the online-based child prostitution business that Mogilyansky allegedly ran with several other people in Moscow, authorities said.