NEW ULM, MINN. - Colleen Hauser and her 13-year-old son Daniel, on the run from court-ordered cancer treatment, were seen in southern California on Tuesday morning, Brown County Sheriff Rich Hoffmann said Wednesday night.

At a hastily assembled news conference, Hoffmann said that the pair was apparently en route to Mexico for an alternative medical treatment to chemotherapy and that he notified the FBI and the federal Immigration and Customs Enforcement agency, which agreed to assist in finding and detaining them. The two disappeared from southern Minnesota on Monday evening and failed to show up for a court hearing here on Tuesday.

Hoffmann said it's unclear how the pair is traveling or who is helping them, but said it's possible that they are already in Mexico. He wouldn't say how his office got the tip, but said he had confirmed the sighting late Wednesday afternoon.

A Brown County sheriff’s dispatcher said this morning that the office had gotten no new information overnight on the whereabouts of Daniel and his mother.

The sheriff's announcement of the sighting in California concluded a day in which a local search became a national manhunt after the boy's father, Anthony Hauser, suggested that Daniel and his mother had left the country.

In an afternoon media briefing, Hoffmann pleaded for Colleen Hauser, 40, to return with her son.

"We just want to talk to her and Danny," he said.

Earlier Wednesday, the Minnesota Bureau of Criminal Apprehension issued a national crime alert with a description of the pair and identifying two other adults who might be with them. The Border Patrol was alerted and Hoffmann said authorities were trying to determine whether Colleen Hauser had a passport or other documents that might enable her and her son to cross the U.S. border. Ten officers in the sheriff's department worked phones and interviewed relatives as tips poured in from around the country. The search has a special urgency because doctors fear Daniel's cancer could worsen rapidly if left untreated.

Daniel was diagnosed in January with Hodgkin's lymphoma, an uncommon but treatable form of cancer. The family ceased his treatment after one session in January, citing religious and other objections, and turned to alternative treatments such as herbs and vitamins. Their decision prompted Daniel's doctors to alert Brown County child protection authorities. A Brown County judge ordered the family to seek treatment, then issued a warrant for Colleen's arrest on Tuesday after she failed to appear in court.

Doctors have testified that the boy has a 90 to 95 percent chance of survival if he gets the recommended chemotherapy and radiation treatment, but only a 5 percent chance of living five years if he goes without conventional treatment.

Father has left message

As the manhunt intensified Wednesday morning, Daniel's father spoke with reporters at the family farm near Sleepy Eye and seemed unworried about the boy's condition. He said he was a "bit disappointed'' by his wife's spur-of-the-moment decision to drop a treatment plan they had agreed on, but said he assumes that his wife had found a suitable alternative form of treatment, and hinted that he knew where.

Asked if he thought his wife and son were still in the United States, Anthony Hauser said, "No, but I'm guessing. I will say this: I left a call [for them] and Canada isn't where I left the call. I'm not saying where.''

Hauser added that he and his wife were open to treating Daniel with a combination of low doses of chemotherapy and alternative medical treatments. "We were going to present a treatment plan to the court. If they didn't go with it, we would appeal it," he said.

Hauser's assessment of his son's disappearance seemed to leave law enforcement authorities in a state of uncertainty.

Hoffmann said the father has been "cooperative'' with the investigation but added, "We can't speculate on the sincerity of the information that Anthony Hauser has provided.''

The mystery facing law enforcement authorities is how a pair with little money and apparently no car could disappear so quickly. Anthony Hauser has said his wife does not have a credit card, did not take the family cell phone and did not appear to have taken checks from the household checkbook.

At the afternoon briefing, Hoffmann said Daniel's name has been entered into the database of the national Missing and Exploited Children's Network. He asked anyone with information about the case to contact his office at 507-233-6700.

The BCA issued a crime alert describing Colleen Hauser as 5-foot-4, 130 pounds, with long "dishwater blonde" hair. It describes Daniel as 5-foot-2 and bald.

It also says they may be in the company of Susan Daya, also known as Susan Hamwi, a California attorney who accompanied them to a medical appointment Monday, or a man named Billy Joe Best, who appeared at a news conference held by the family in early May to say he supported the Hausers. Best, of Boston, ran away from home at the age of 16 after five chemotherapy treatments and returned home after his parents pleaded with him on television.

But Best, reached Wednesday by the Star Tribune, said he is home in Boston and had no involvement in their flight.

Natural healers react

Word of the manhunt also spread quickly through the national Nemenhah movement, a Native American religious group that the Hausers joined because of its support for natural healing methods.

Phillip (Cloudpiler) Landis, the band's principal medicine chief, said Tuesday that he was "floored'' by Colleen and Daniel's disappearance and said that defying a court order was a mistake.

"The only advice I would give them is get your butts home,'' Landis said. "It's lamentable, but you've got to work with the judge. There isn't a choice.''

Landis said he hadn't spoken with the Hausers since May 11 and doesn't know if other Nemenhah members are involved in the pair's flight.

In southern Minnesota, however, the pair's disappearance triggered much consternation.

In St. Peter, Daniel's court-appointed attorney, Philip Elbert, said he is "very, very worried about Daniel, about his health and about his future. I'm here to represent his best interests, but I've got to talk with him to find out what he wants."

Elbert asked Brown County District Judge John Rodenberg on Tuesday to remove Daniel from his parents after he did not appear in court.

Sheriff Hoffmann, too, showed the strain of the intense search. Briefing reporters Wednesday afternoon on the progress of the investigation, he paused and issued a direct appeal for the mother and the boy to turn themselves in.

"The main thing I want to say," Hoffmann said, "is Colleen Hauser should come home and talk to us."

Staff writers Chao Xiong, Bob von Sternberg, Jenna Ross contributed to this report. curt.brown@startribune.com • 612-673-4767 wolfe@startribune.com • 612-563-7253