- The missing boy's father takes polygraphs and is "ready to assist" authorities
- His lawyer says the father had not seen his two children since December
- Bellevue, Washington, police receive 900 tips, but nothing "actionable"
- Sky Metalwala disappeared 9 days ago in suburban Seattle
The search for a 2-year old boy who went missing in suburban Seattle more than a week ago continued Monday with no new suspects or information in the case, Bellevue, Washington, police said.
Maj. Mike Johnson said his department had received 900 tips in the boy's disappearance, but none "have led to any high-priority actionable evidence."
Though none of those leads has led to a breakthrough in the investigation, Johnson urged the public to continue providing information in the case. He said the case could eventually become a "criminal investigation," but "we're not there."
"All theories are viable, " Johnson said. "We have not ruled anything out as a possibility in this case. ... The thing that we're lacking is evidence."
Over the weekend, Johnson said police had expanded the search radius at the apartment in Redmond where toddler Sky Metalwala lived with his mother, Julia Biryukova, and the wooded area where she told police she last saw her son nine days ago.
The brown-eyed boy with short, dark hair was last seen wearing a dark-green hooded sweatshirt and blue-and-gray-striped pants.
On Friday, Johnson said the police were "frustrated by the lack of information we're getting" from the boy's mother. According to Johnson, Biryukova initially reported that she'd run out of gas early November 6 in Bellevue, just east of Seattle, leaving the toddler in the car while she took her 4-year-old with her to get help.
Police later determined that the car had gas and was working.
"I'll let the evidence speak for itself, which is: There was gas in the car; the car was able to drive and operate," Johnson said. "That's not what Julia told us."
But on Monday, Johnson told reporters that he was "not comfortable calling her a person of interest or a suspect." He said the boy's mother "continues to cooperate," though she has not responded to requests issued through her attorney "to come and talk to us at length."
"It's something we're going to keep trying to do," the police major said of the outreach efforts to Biryukova.
Other than the boy's mother and his 4-year-old sister, no one has reported seeing the toddler in the past two weeks, police spokeswoman Carla Lafrate said last week.
Attorneys for Biryukova have declined to comment to CNN about the case, citing the ongoing investigation. Repeated attempts to reach Biryukova by CNN affiliates in the Bellevue and Redmond area have been unsuccessful.
The father, Solomon Metalwala, who is separated from Biryukova, told HLN's Nancy Grace on Monday that he'd taken two polygraph tests in recent weeks, declining to offer details on whether he'd passed them or what questions he answered.
"He's always ready to assist law enforcement in any way," added his attorney, Leslie Clay Terry III.
Solomon Metalwala said he hadn't seen the children since December, having lost custody of them. He added that he was getting ready for church the Sunday morning of November 6 when Biryukova reportedly woke the children up earlier to take his young son, Sky, for treatment at an area hospital.
"We've tried since January to get the children out of (Biryukova's) custody," Terry told HLN.
Court records indicate Sky's parents have had a tumultuous relationship.
Biryukova has said she feared for her safety and that of her children around the elder Metalwala, according to records.
"I am told by my husband Solomon (and) his family that if I take any action towards custody of our children he will take them out of the country (and) I will never see them again," she wrote in court papers.
Metalwala responded in court filings that his wife suffered from mental health problems and was unable to care for the children on her own.
Both parents were charged in 2009 with reckless endangerment for leaving then-3-month-old Sky alone in their parked car. Court records show they completed court-ordered parenting courses following the incident.