FREMONT -- A 25-year-old mortgage broker from Fremont was among 14 defendants charged in what federal officials said is one of the largest online child exploitation investigations ever conducted by U.S. Immigration and Customs Enforcement's Homeland Security Investigations.

Fremont resident Aung Gaw, also known as Michael Gaw, faces one count of receipt of child pornography in connection to the illicit online scheme that agents say involved more than 250 victims in 39 states and five countries.

Gaw, who worked as an account executive for a mortgage brokerage in Fremont -- and attended UC Berkeley, stands accused in the case, which targeted child porn posted on an anonymous website, federal authorities said Tuesday.

He was arrested at his home in the 39000 block of Sonora Court on Nov. 5 after authorities conducted a search warrant there, ICE spokeswoman Virginia Kice said.

His home is located in the city's Sundale neighborhood, just northeast of Blacow Road and Mowry Avenue, near Sutter Drive.

Federal court records show Gaw is set for jury trial June 23.

His 13 co-defendants were later indicted on charges of allegedly conspiring to operate a child exploitation enterprise following an international investigation by HSI and the U.S. Postal Inspection Service. All 14 defendants were in federal custody Tuesday, authorities said.

In this case, Kice said the victims -- males ages 15 and younger -- were enticed into posting sexual images of themselves that were later shared online. Kice said users of an underground network posed online as girls to coax boys into sharing the pornographic images.

As of Tuesday, investigators had identified 251 child victims, including 228 in the United States. The victims were contacted by law enforcement, and the U.S. victims were offered support services from victim assistance specialists.

"Never before in the history of this agency have we identified and located this many minor victims in the course of a single child exploitation investigation," ICE Deputy Director Daniel Ragsdale wrote in a statement released to the media.

The website's alleged primary administrator, Jonathan Johnson, 27, of Abita Springs, La., was charged with operating a child exploitation enterprise. He admitted to creating multiple fake female personas on popular social networks to target and sexually exploit children, and to coaching other child predators in his inner circle to do the same, according to ICE's release. Johnson has been in federal custody since his June 13 arrest. He faces 20 years to life in prison if convicted.

Also charged: Daniel Nolan Devor, 39, of Brunswick, Ga. -- conspiracy to produce child pornography, distribution of child pornography and receipt of materials involving the sexual exploitation of minors; John C. Foster, 44, of Tipp City, Ohio -- conspiracy to produce child pornography, distribution of child pornography and receipt of materials involving the sexual exploitation of minors; Vittorio Francesco Gonzalez-Castillo, 26, of Tucson, Ariz. -- conspiracy to produce child pornography; Sean Jabbar, 32, of Minneapolis, -- receipt of child pornography; Christopher Jamieson, 30, of Douglasville, Ga. -- receipt of child pornography; Andrew Korpal, 29, of Granger, Ind. -- receipt of child pornography; Nicholas Saine, 27, of Seattle -- receipt of child pornography; Christopher Schwab, 25 of New Orleans -- production of child pornography, distribution of child pornography and receipt of child pornography; Stanley Zdon III, 27, of Tuckerton, N.J. -- conspiracy to produce child pornography; Roy Naim, 30, of Brooklyn, N.Y. -- conspiracy to produce child pornography, attempted sexual exploitation of a child, receipt of child pornography and possession of child pornography; Minh Vi Thong, 30, of Denver -- production of child pornography, distribution of child pornography and possession of child pornography; and Michael Eales, 24, of Westby, Wis. -- production of child pornography. Eales was sentenced Oct. 29, 2013, and ordered to serve two concurrent 30-year terms in federal prison followed by a lifetime of supervised release for manufacturing child pornography, federal officials said.

Anyone with information about suspected child predators or related suspicious activity is asked to call HSI's toll-free hotline at 1-866-DHS-2-ICE. Suspected child sexual exploitation or missing children may be reported to the National Center for Missing & Exploited Children through its toll-free 24-hour hotline: 1-800-THE-LOST.

Contact Natalie Neysa Alund at 510-293-2469. Follow her at Twitter.com/nataliealund.