The CEO of a company that boasts being the largest privately owned online investigative service was arrested at a hackers' conference in New York City and charged with impersonating an FBI agent to intimidate a federal witness.

Agents descended on Pallorium Inc. CEO Steven Rombom, also known as Steven Rambam, just before he was scheduled to speak at HOPE (Hackers On Planet Earth) Number Six.

According to a complaint filed Friday in the Southern District Court of New York, Rombom visited the in-laws and wife of a confidential informant involved in an open money laundering case against former Brooklyn prosecutor Albert Santoro.

Federal prosecutors have charged Santoro with participating in a money-laundering scheme in which participants invested money from large financial institutions in losing stocks to benefit their co-conspirators. The investigation resulted in the arrest of 47 people. Santoro has maintained his innocence and his lawyer has claimed that the confidential informant entrapped him.

Santoro's trial is pending, and the last activity in that case was April 2006, when Rombom allegedly impersonated a federal officer.

Through his attorney, Santoro hired Rombom to investigate the confidential informant, according to the court complaint filed Friday. The informant's in-laws told FBI agents that Rombom showed up at their California home, flashed what appeared to be a badge and told them he was a federal agent investigating the informant, according to the complaint. He then showed photographs of the federal witness, explained that the witness was a "bad and dangerous person" who had been in prison and claimed to be concerned about the safety of their daughter, who is also the wife of the informant, an FBI agent stated in court documents.

Later, when the wife arrived, Rombom allegedly repeated the assertion and asked questions about where the informant worked, according to court documents.

A call to Pallorium was not returned Monday and attempts to find a residential listing under "Steven Rombom" and "Steven Rambam" were unsuccessful.

The company Web site states that Rombom is the basis of a character in the Kinky Friedman series of murder mystery novels.