LAS VEGAS, Nevada (CNN) -- The search for 6-year-old Cole Puffinburger continues even though an Amber Alert for the boy was canceled.

Police on Saturday deactivated an Amber Alert for Cole, who was abducted Wednesday from his Las Vegas, Nevada, home, in what authorities are calling a drug-related kidnapping.

The alert was canceled because police believed that it had "run its course," said Capt. Vince Cannito of the Las Vegas Metropolitan Police.

Cannito also said authorities had interviewed Cole's grandfather, who was arrested Friday night in California, and were looking for another person of interest in the abduction.

Clemons F. Tinnemeyer, 51, was arrested in Riverside, California, and booked into the San Bernardino County Sheriff's Central Detention facility, the county sheriff said. The detention facility's Web site said Tinnemeyer is not eligible for bail.

It was unclear what charges Tinnemeyer was booked on or might face. A San Bernardino County sheriff's spokeswoman referred questions to federal officials. An FBI spokeswoman did not immediately return a call seeking comment.

Las Vegas Metropolitan Police said Friday that Tinnemeyer was sought for questioning in the kidnapping of Cole. Police say the boy was snatched from his home Wednesday by three armed men who tied up his mother and her fiance and ransacked the home, taking the child when no money was found.

Cannito said that Tinnemeyer had been involved in "significant drug dealing" worth millions of dollars and that Cole was kidnapped by drug dealers attempting to recover lost money and property. Watch why police want to talk to Tinnemeyer »

Authorities believe that Tinnemeyer may have stolen millions from a Mexican drug cartel, the Las Vegas Review-Journal reported Friday and Saturday, citing police and other sources. Police refused to say what role Tinnemeyer may have played in the drug operation or whether the kidnappers were seeking a ransom.

Police believe that methamphetamine was involved, Officer Cris Johnson told the newspaper.

Tinnemeyer last contacted his family in August, authorities said Friday, and had been reported missing last month.

Meanwhile, the boy's father issued an emotional plea for his release.

"I can't comprehend why somebody would do something like this to somebody and take a kid like that, take my son and do something like that," Robert Puffinburger said. "Just bring him home. If you've got him, bring him home. Drop him off somewhere, I don't care. Just -- just let him go."

Police said that at least two of the three men posed as police officers to enter Cole's home about 7:25 a.m. Wednesday.

Cole is described as 3 feet 11 inches tall and weighing 48 pounds, with blond hair and blue eyes. He was wearing a sweatshirt, dark jeans and silver-rimmed prescription glasses, authorities said.

The suspects were described as three Hispanic men who spoke with heavy accents.

National and local authorities have said that such drug-related abductions are happening more frequently in communities near the Mexican border.