HICKORY, N.C. — Investigators searching for a missing 10-year-old girl said Tuesday that they have recovered a mattress from a Caldwell County landfill that they will examine for evidence in the case.

Landfill workers discovered the mattress while they were re-grading an area that was searched last week, police said. DNA evidence was found on the mattress, police said, and it will be tested to determine if it is connected to Zahra Clare Baker's disappearance.

Baker was reported missing on Oct. 9. Police believe the girl is dead, and authorities in recent weeks have combed wooded areas and a landfill for evidence or her body.

Her stepmother, Elisa Baker, has been charged with obstruction of justice in the case. Police said she acknowledged to writing a bogus ransom note found the day Zahra was reported missing.

Elisa Baker, 42, has been talking with investigators after her lawyer approached police offering her help, said Maj. Clyde Deal, deputy police chief in Hickory.

Deal said Tuesday that Elisa Baker was taken this week to a home where she once lived, but he declined to elaborate.

“We’re working with her attorney to see what information she has and what she is willing to share. We’re treating her like every other source of information,” he said.

A telephone message left for Elisa Baker’s attorney, Scott Reilly, was not immediately returned.

The girl’s father, Adam Baker, was arrested Monday on unrelated charges. He and his daughter are from Australia, and they moved to North Carolina in 2008 after he married Elisa Baker, whom he had met on the Internet.

Adam Baker, 33, is facing one count each of assault with a deadly weapon and failure to return rental property, two counts of communicating threats and five counts of writing worthless checks, authorities said.

The timing of his arrest raises questions because the charges against him were filed over the past few months. Hickory Police Chief Tom Adkins had said authorities delayed taking action because he was cooperating with police.

Deal said investigators haven’t talked to Adam Baker since his arrest. He also said Adam Baker did not have an attorney.

Adam Baker was being held in a western North Carolina jail on $7,000 bond. Elisa Baker is at the same jail.