The suspect in the murder of American child beauty queen JonBenet Ramsey was treated at a Bangkok clinic specializing in sex-change operations and cosmetic surgery, clinic officials said Sunday.

A doctor at the Pratunam Polyclinic confirmed that he had treated the suspect, 41-year-old former schoolteacher John Mark Karr.

"He was one of my patients," said Dr. Thep Vechwijit, who declined to provide details of the treatment.

A staffer at the clinic, who demanded anonymity since she was not authorized to make statements to the media, said Karr had consulted the doctor about a sex-change operation.

This could not be confirmed by other sources.

Timeline: The JonBenet Ramsey Murder Investigation

Karr was to be flown later Sunday to Boulder, Colorado, where he faces charges of first-degree murder, kidnapping and child sexual assault in connection with the 1996 killing of 6-year-old JonBenet Ramsey.

Police said Karr appeared nervous ahead of his deportation.

"Generally he is fine, but a little bit nervous as the time of his departure approaches," immigration police chief Lt. Gen. Suwat Tumrongsiskul told The Associated Press.

"We treat him well since he is a high-profile suspect. Yesterday he said that he wanted to eat American food so we ordered from Kentucky Fried Chicken for him, but this morning he had the standard breakfast" of Thai food, Suwat said.

The case has sparked concern in Thailand over whether foreign teachers hired by Thai schools are adequately checked to weed out criminals and deviants.

Karr, once detained on charges of possessing child pornography, in recent years apparently traveled to Europe, Central America and Asia to search for teaching jobs. He was arrested a day after he began teaching second grade in Bangkok, U.S. prosecutors said.

Thai Education Minister Chaturon Chaisang said Saturday he has ordered his ministry to look into the problem.

Chaturon said it has been too easy for unqualified foreigners to get teaching jobs, in part because those with proper qualifications are too expensive for many institutions, the state Thai News Agency reported.

U.S. officials, the only ones to have actually interrogated Karr, have been silent about what he told them, citing his right to privacy and legal procedures, while secondhand accounts by Thai officials have been vague and contradictory.

When Karr spoke to reporters on Thursday, he said he was alone with JonBenet when she died in the basement of her home on Dec. 26, 1996, but that her death was an accident.

"I am so very sorry for what happened to JonBenet," Karr told The Associated Press. "It's very important for me that everyone knows that I love her very much, that her death was unintentional, that it was an accident."

Although Karr took responsibility for the girl's death, his statements have been sketchy, and with little public evidence linking him to the crime, some experts have speculated that he is either lying or delusional.

"Many high-publicity crimes have these people coming out of the woodwork," said Elizabeth Loftus, director of the Center for Psychology and Law at the University of California-Irvine.

More than 200 people confessed to the 1932 kidnapping and murder of Charles Lindbergh's infant son. The 1947 "Black Dahlia" murder — the slaying of aspiring actress Elizabeth Short, who was found sliced in half in a vacant Los Angeles lot — also attracted numerous spurious confessions.

Lawyers for the Ramsey family said Friday that a number of people have already confessed to the killing of JonBenet, none of them with enough credibility to attract the attention of law enforcement.

More coverage is available in FOXNews.com's Crime Center.