It's been more than a week since the disappearance of 6-year-old Isabella Kalua in Waimanalo, Hawaii. The search for Isabella continues, as Honolulu police and volunteers spread across the city to find the missing child.

       Isabella was last seen asleep in her room at her Puha Street address on Sunday, Sept. 12 around 9 p.m., local time, according to the Honolulu Police Department.

       Her adoptive family has not participated in search crews, but their attorney told KITV that they have spoken and are cooperating with police. Since they have received death threats regarding the child's disappearance they have not gone out to search, the attorney said.

       MORE: Search is on for missing 6-year-old in Hawaii

       KITV reports that HPD has acquired several items that may be linked to Isabella, including a photo album and toys found in a garbage bag, but they have yet to confirm its connection to the case.

       Police are also working with the FBI to investigate her disappearance.

       Courtesy of Honolulu Police Department via AP

       Isabella Kalua is seen here in an undated file photo is missing. She was last seen sleeping in her room in Waimanalo, Oahu, Hawaii, Sept. 12, 2021, Honolulu police said.

       "We have conducted numerous interviews; however, there are still individuals, to include acquaintances and family members, who have yet to come forward to be interviewed," HPD said in a statement to KITV.

       Honolulu Police say it won't rule out foul play.

       MORE: Hawaii locals beg tourists to stay home, citing COVID-19 concerns

       "I don't want to think the worst-case scenario," Alena Kaeo, Kalua's biological aunt told ABC-affiliate KITV. "But it is always is a possibility. Again, I'm trying to keep my faith as strong as possible and I pray -- I pray hard that she is safe. I don't want to think the worst but it is a possibility."

       Isabella is described by authorities as being a brown-eyed, brown-haired, white, and mixed-race girl. Police said Isabella was likely wearing a black hoodie, black leggings, colorful socks, and Nike slides when she went missing.

       MORE: Body 'consistent with description' of Gabby Petito found in Bridger-Teton National Forest