A photojournalist at the University of Hawai'i admitted to posting photos and the identities of three undercover agents with the Drug Enforcement Administration on a Web site dedicated to outing undercover law enforcement officers and informants, federal prosecutors said.

Christopher Yeung obtained the photos from a surveillance tape turned over to criminal lawyers defending his father, a Honolulu doctor on trial for allegedly selling prescription drugs, according to the U.S. attorney's office.

Yeung, who also is a legal aide with his father's defense team, told Magistrate Judge Kevin S.C. Chang earlier this year that he posted the photos on the Web site http://WhosaRat.com after editing them out of the surveillance film, which was turned over to his father's attorneys during discovery, said Assistant U.S. Attorney Jonathan M.F. Loo.

Prosecutors and law enforcement officials nationwide have expressed concern over the Web site, saying undercover agents could be harmed if their identities are revealed.

The DEA agents involved have not been reassigned or transferred, according to the U.S. attorney's office. Anthony D. Williams, assistant special agent in charge of the U.S. Drug Enforcement Administration's Ho-nolulu district office, would not comment yesterday and forwarded all questions about the agents involved to the U.S. Attorney's Office.

The surveillance film depicts Yeung's father, Dr. Kachun Clement Yeung, meeting with three undercover DEA agents posing as patients. The online posting named the three agents.

"What he did, in these circumstances, is not illegal. This investigation was essentially done," Loo said Friday. "If it had been (posted) in the context of an ongoing investigation, that's another situation entirely and much more problematic. I don't know that there is anything that can be done until someone crosses the line and obstructs justice. Obviously, it's a concern, you don't expect materials turned over to the defense during discovery to be thrown out there for public consumption."

Calls to Christopher Yeung on Thursday, Friday and yesterday at the offices of the UH newspaper Ka Leo O Hawai'i, where he is the photo editor, were not returned. Two calls to his residence Friday and another yesterday were not returned.

Yeung posted the pictures and used the e-mail address photo@kaleo.org as the return address, Loo said.

Calls to Kachun Yeung at his office and his home Friday and yesterday were not returned. His attorney, Samuel P. King Jr., would not comment Friday.

The court became aware of Christopher Yeung's posting after Loo raised the issue during a court hearing. Yeung addressed the court and admitted to the postings, Loo said.

Kachun Yeung, 53, was indicted by a federal grand jury in April on 30 counts of writing illegal prescriptions and 19 counts of Medicaid fraud.

Kachun Yeung is accused of prescribing a painkiller, OxyContin, the trade name for Oxycodone, "outside the course of professional medical practice and not for a legitimate medical purpose."

The prescription charges each carry up to 20 years in prison. The Medicaid fraud counts each carry up to 10 years in prison.

Yeung is free on bond and can still practice medicine, but had to surrender his DEA certificate permitting him to prescribe controlled drugs.

Kachun Yeung's arrest April 3 resulted from investigations by the DEA, in partnership with the U.S. Department of Health and Human Services, the FBI, the U.S. Postal Inspection Service, the Internal Revenue Service, the state of Hawai'i Department of Public Safety Narcotics Enforcement Division, the state of Hawai'i Department of Commerce & Consumer Affairs Insurance Fraud Investigation Branch and the Honolulu Police Department.

Jay Hartwell, faculty media adviser at UH-Manoa, said Friday that Christopher Yeung is still employed at Ka Leo. Hartwell said he did not know much about the situation other than what he had been told by local media. He would not comment further.

Police and prosecutors are worried that WhosaRat.com, which claims to identify more than 4,000 informants and undercover agents, will cripple investigations and endanger witnesses.

The WhosaRat.com Web site first caught the attention of authorities after a Massachusetts man put it online and named a few dozen people as turncoats in 2004. Since then, it has grown into a clearinghouse for mug shots, court papers and rumors.

Federal prosecutors and law enforcement officials say the site was set up to encourage violence, and federal judges nationwide were recently warned that witnesses in their courtrooms may be profiled online.

"I can't think of anything much more irresponsible for somebody to do. To me it seems like it's really stupid," Charles L. Goodwin, special agent in charge of the FBI's Honolulu division, said Friday. "If they're outed like that, it is exposing them to the criminal element in their undercover capacity and they may not be aware of it. The best-case scenario, it ruins an investigation, and the worst-case scenario is that it gets somebody killed."

Sean Bucci, a former Boston-area disc jockey, set up WhosaRat .com after federal prosecutors charged him with selling marijuana in bulk from his house. Bucci is under house arrest awaiting trial and could not be reached, but a WhosaRat spokesman identifying himself as Anthony Capone said the site is a resource for criminal defendants and does not condone violence.

"If people got hurt or killed, it's kind of on them. They knew the dangers of becoming an informant," Capone told The Associated Press. "We'd feel bad, don't get me wrong, but things happen to people. If they decide to become an informant, with or without the Web site, that's a possibility."

In documents filed in Bucci's court case last month, federal prosecutors said they have information that Bucci set up the Web site to help intimidate and harm witnesses.

"Such information not only compromises pending or future government investigations, but places informants and undercover agents in potentially grave danger," Assistant U.S. Attorney Peter K. Levitt wrote.

In the case involving the UH newspaper photo editor, UH-Manoa spokesman Jim Manke said Thursday that students who use university e-mail addresses to post something illegal or inappropriate would be subject to the university computing policy and appropriate disciplinary action.

However, if a student were to use a Ka Leo e-mail account, this would not be subject to the policy because the Ka Leo Web site is hosted by a third-party server.

According to the university's information technology resource policy, university computers may not be used for illegal or inappropriate purposes.

Ka Leo is considered semi-autonomous from the university but computing equipment used by Ka Leo staff, while purchased using student fees, is considered property of the university, Hartwell said.

Manke said the posting involving the Ka Leo photo editor had not been brought to the attention of information technology officials.

Reach Peter Boylan at pboylan@honoluluadvertiser.com.