LAS VEGAS, Nevada (CNN) -- Police said they are looking for the grandfather of a boy who was snatched from his Las Vegas, Nevada, home Wednesday by men posing as police officers.

Clemens F. Tinnemeyer, 51, is being sought for questioning in the case of 6-year-old Cole Puffinburger.

Police Capt. Vincent Cannito said Tinnemeyer has been involved in "significant drug dealing" worth millions of dollars.

Tinnemeyer owns a sightseeing motor home service and works as a driver, police said in a written statement.

He was last seen in Las Vegas on May 21, 2008. At the time, he was driving a white Dodge extended-cab pickup with Mississippi license plates KA6251.

He last contacted his family in August and was reported missing in September.

Authorities said Thursday that the case is related to "illegal narcotics activity" and that the family was targeted; Cannito said Friday that Cole was kidnapped by drug dealers attempting to recover lost money and property.

"These are extremely dangerous people," Cannito said. "This is as bad as it gets."

At least two of the three suspects posed as police officers to enter Cole's home about 7:25 a.m. Wednesday, police said. They tied up the boy's mother and her fiancé and ransacked the house before kidnapping the boy when no money was found, they said.

Don't Miss KVVU: Missing boy case involves drugs

In a story published Friday, The Las Vegas Review-Journal quoted unnamed sources as saying a member of the boy's family owes a Mexican drug cartel between $8 million and $20 million, describing the relative as an alleged money launderer for the cartel and saying the person was in hiding.

A search for the boy spans much of the American Southwest, and a nationwide Amber Alert was in effect.

Cole is described as being 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 kidnappers were described as three Hispanic men who spoke with heavy accents.

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

Anyone with more information is asked to call Las Vegas Metropolitan Police at 702-828-5678.

All About Kidnapping • Nevada