SAN DIEGO -- Rewards related to 7-year-old Danielle van Dam's disappearance have soared to $185,000, even as police acknowledged the odds of finding the second-grader alive are waning.

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Despite their diminished hope, investigators will do "whatever it takes" to find Danielle, San Diego police Lt. Jim Duncan said Tuesday.

"This is the highest priority they have, and they're working on it night and day," he said.

But, he added: "We are not real hopeful on her condition."

A retired San Diego phone company owner named Don Blakstad Tuesday added his own $100,000 reward to the $85,000 in reward funds previously announced.

On Monday, the van Dam family offered $25,000 for their daughter's safe return and San Diego bail bondsman George "King" Stahlman put up $50,000 for information leading to whoever is responsible for her disappearance.

It is assumed that a reward of $10,000 offered by the Millennium Children's Fund still stands, despite a rather public rift between the charity's head and the van Dam family.

Blakstad's reward offer was based on the girl's safe return, according to his attorney, Charlie Becker.

A fund-raiser will be held Thursday night at the Pat and Oscar's Restaurant in Carmel Mountain Ranch. Proceeds will go to assist in the search for Danielle.

Also Tuesday, authorities took a highly trained tracking dog through the van Dam home in hopes of turning up clues that will clear up the mystery of her disappearance.

Officers led the bloodhound, on loan from the Riverside County Sheriff's Department, from room to room in the van Dams' northern San Diego house and through their yard late in the afternoon.

"We're going to try to pick up a scent," Duncan said. "This dog is different than the dogs we used the other day, and it's supposed to be maybe a little bit better-trained."

Investigators said they were unsatisfied with a canine search of the two-story Sabre Springs home they conducted within the first few days of the 7-year-old's presumed kidnapping.

"The FBI has utilized this particular dog in the past, and they felt very confident in its abilities," Duncan said of the hound.

Officials would not say if the brown-and-black, floppy-eared dog seemed to have detected anything of value.

Danielle's disappearance 12 days ago has generated intense searching, heavy national news coverage and the rewards.

When they filed a missing-person report the morning of Feb. 2, Brenda and Damon van Dam told authorities that the last they'd seen of their daughter was when the father put her to bed after 10 o'clock the night before.

Since then, various law enforcement agencies and teams of citizen volunteers have searched the upper-middle class neighborhood and its environs, as well as large sections of the Imperial County desert.

The sun-baked region near Arizona became a focus of the investigation when authorities learned that a man who lives two doors away from the van Dams traveled there around the time the girl vanished.

The neighbor, 50-year-old David A. Westerfield, apparently took his recreational vehicle to a spot near Glamis over the weekend of Feb. 2-3.

Duncan said the investigation remained focused on the self-employed design engineer and off-roading enthusiast. Detectives have twice gone through his house with service dogs.

During those searches, officers carted off 13 boxes and bags full of household items. Included in those boxes and bags of evidence was an unknown amount of child pornography, according to 10News.

In addition, police impounded Westerfield's sport utility vehicle and the motor home he took to the desert.

Duncan said that a DNA sample submitted by Westerfield to police has been forwarded to the FBI crime lab in Washington, D.C.

Westerfield has hired criminal defense attorney Steven Feldman to represent him in the case, although he has not been charged with any offense.

No arrest in the case is imminent, Duncan said.