A Russian-born former Goldman Sachs computer programmer accused of stealing secret trading codes from the investment bank was being held in federal custody Monday, pending the posting of $750,000 bail.

Sergei Aleinikov, 39, was ordered by U.S. Magistrate Kevin Nathaniel Fox in Manhattan on Saturday to post a $750,000 personal recognizance bond to be secured by three financially responsible people.

The bond also was to include $75,000 in cash, and Aleinikov was ordered to surrender his passport.

Aleinikov, a Russian immigrant living in New Jersey, was arrested on Friday night by FBI agents at Newark Liberty International Airport after returning from Chicago, according to court documents.

He is accused of “theft of trade secrets” related to computer codes used for automated stock and commodities trading at an unspecified financial firm.

Sources familiar with the situation have told Reuters that the financial institution is Goldman Sachs.

A Goldman representative declined to comment Monday. A lawyer for Aleinikov, Sabrina Shroff, also declined to comment.

Authorities contend that Aleinikov improperly copied a financial institution’s proprietary computer code and then uploaded it to a computer server in Germany.

In court papers, an FBI agent said Aleinikov worked at an unspecified financial institution as a programmer from May 2007 until June 5, when he left to work for a new company focused on high-volume, automated trading.

The case could shed light on the intricate trading systems developed by Goldman and also raises questions about the security of Wall Street’s proprietary trading operations.