ISSAQUAH, Wash. -- A search at Tiger Mountain for a missing 12-year-old Tacoma girl has been suspended, police said.

A tip led investigators to the site, and a command post was set up along Highway 18 on Tuesday. A helicopter and dozens of people, some with dogs, took part in the search for 12-year-old Zina Linnik, who disappeared on July 4.

Officials met overnight and decided to suspend the search, police said. There were no immediate further details.

Meanwhile, police said they are investigating a convicted sex offender in connection with Linnik's disappearance.

Police searched the man's van and Parkland home on Sunday and Monday, and seized more than 65 items, including articles of bedding and girls' undergarments, according to a court documents obtained by the Tacoma News Tribune.

Police said the van matched the description given by Zina Linnik's father at the time of her disappearance.

The man, who has not been charged in the case, was convicted of incest in the first degree in 1990. His home is less than 10 miles from Linnik's in Tacoma.

Police said detectives questioned him and then handed him over to federal officials because of immigration violations.

Linnik had been watching fireworks when a family member heard her scream and saw a van speed away.

The van, an older gray model, was spotted leaving the scene at about 9:45 p.m. A witness told police the van's license plate included the numbers 677 or 667.

The Washington State Patrol Troopers Association and the FBI are offering a $15,000 combined reward for information leading to the safe return of Linnik.

The girl is described as being 4 feet 10 inches tall and weighing 80 pounds, with blond hair worn in a ponytail. She was last seen wearing a pink T-shirt, pink, orange and yellow capri pants, and red flip-flop sandals.

Police ask that anyone with information on the case call them at 253-830-6508.