In an unusual step, they're releasing a series of photographs, from which the child has been digitally removed, in an effort to get the public's help.
CBS News correspondent Jim Acosta reports that the girl is believed to be white, blonde and 9 to 12 years old. She is possibly from the northeastern U.S or southeastern Canada and was abused by somebody, possibly a relative or caregiver, who posted the photos on child pornography Web sites.
Anyone with information can log on to to www.ice.Gov or call the National Center For Missing & Exploited Children cyber tipline at 1-800-843-5678.
Using the background in some of the photos, which have been on the Web for more than a year, authorities have identified as the crime scene one of the rooms in Disney World's Port Orleans French Quarter resort. Disney officials and authorities in Florida's Orange County are said to be cooperating with Canadian authorities in the case.
"We are in the middle of questioning staff that have been there since that time period, going through logs, because we have a lot of information on what the inside of the hotel room looks like," Sgt. Paul Gillespie of the Toronto Police Service told Acosta.
Officials said they took the unusual step of releasing the photos in the hope that someone who was there at the time might recognize the room and other locations at the theme park and perhaps lead police to the little girl and the culprit. The pictures showed an elevator, a fountain and a bed in a hotel room.
In an interview Wednesday on The Early Show , Marcy Forman, director of the office of investigations for the Immigration and Custom Enforcement Agency (ICE), said officials are worried about the child's safety.
"The faster we find her, the easier we could rest," Forman said. "We're working diligently with the sheriff's office in Florida and with the Toronto police department."
ICE is a division of the Department of Homeland Security which in 2003 started Operation Predator to identify, investigate and arrest sexual predators. Forman said it had been cooperating in the case, even before the crime scene was identified as a Florida hotel.
Why didn't officials release a photo of the girl, even just her face?
"In some instances, it helps to identify the victim," said Forman. "But in most instances, we want to protect the privacy and the safety of the victim. That's why we are only releasing the photos of the location we believe that the abuse took place."
Officials say more than 50,000 children are being used for Internet pornography and so far only about 500 of them have been identified.
Toronto police reportedly has one of the largest and most sophisticated child pornography units in North America. The girl came to the attention of the then two-year-old unit in 2002.