Revelations about his interest in child murders, an apparent alibi from an ex-wife and the stunning comments from 41-year-old John Mark Karr himself have raised questions about whether he was responsible for JonBenet's 1996 killing.

Thai officials said they had revoked Karr's visa, clearing the way for his deportation to the United States, where the first arrest in the decade-old case has sparked another frenzy of wall-to-wall media coverage.

"He likely will leave Thailand on Sunday but the United States has not yet been able to confirm his flight," a senior immigration police official told AFP on condition of anonymity.

Arrested Wednesday at his Bangkok apartment, Karr on Thursday said he had been with JonBenet in the basement of her family's Colorado home, where her beaten and strangled body was discovered the day after Christmas.

Thai police said Thursday that he had confessed to killing her unintentionally. But asked by reporters if he had done so, Karr said: "No, I did not. It was an accident."

Thai police said he told them that he was "in love" with the girl, who was often pictured in lipstick or mimicking seductive adult poses in her frequent appearances in child beauty pageants.

Karr's arrest came just a day after he had begun working as a second-grade teacher at an international school in Bangkok. US media reports said he had married his two former wives when they were teens, one just 13 years old.

Both wives reportedly later said they had been coerced but the second appeared to offer her estranged husband a lifeline after his purported confession, saying they were together when JonBenet's body was found.

Lara Karr said that on December 26, 1986, when the body was discovered in Colorado, she, her husband and their three sons were together in the southeastern state of Alabama, a US television station in California reported.

Her comments were not reported directly, but paraphrased by a reporter in Petaluma, a town in northern California.

Lara Karr said her ex-husband had spent a lot of time studying the unsolved cases of Ramsey and Polly Klaas, who was abducted from her Petaluma home and slain in 1993, the station said.

Meanwhile the Denver Post newspaper reported that a veteran Denver attorney Phil Cherner, who has represented clients who have falsely confessed, said he saw evidence the suspect was lying.

"This guy seems to be not just confessing, but openly inviting everyone to a microphone to hear him confess. That raises questions in my mind as to his guilt," Cherner was quoted as saying.

In Boulder, Colorado, District Attorney Mary Lacy said it had taken months to track down Karr and that more work needed to be done on the case.

Lacy said authorities would have preferred to conduct their investigation out of the public eye, but that circumstances can sometimes warrant an arrest "before an investigation is complete."

"Exigent circumstances" -- such as a fear of flight or a desire to ensure public safety -- "can drive the timing of an arrest," she said.

JonBenet's murder raised the curtain on the world of child beauty pageants, as television reports showed the young child wearing lipstick, jewelry and gowns, posing in cowgirl outfits or seductive dresses and gowns.

Suspicion was cast on her parents and even her then nine-year-old brother, but her family insisted that an intruder must have got into the house and murdered her. An autopsy showed she might have been sexually assaulted.

"I hope they can test him (for DNA) as soon as possible so they can exonerate him," the suspect's brother Nate Karr told the Atlanta Journal-Constitution newspaper. "He's innocent."

Agence France Presse