Josh Powell provided West Valley City police with DNA on Tuesday, which is routine in missing persons investigations, Scott Williams said.
"On the possibility that some DNA of some evidentiary value is ultimately obtained, the police need a DNA profile from as many people as possible," he said.
Police have said Josh Powell is not a suspect in the disappearance of his wife, Susan Powell, who was reported missing Dec. 7 when she didn't show up to work and her two children were not dropped off at day care.
Josh Powell has told police he went camping with their boys, ages 2 and 4, in subfreezing temperatures about 12:30 a.m. that day and returned in the evening.
Investigators said they haven't been able to verify the camping trip because snow has covered the site - Simpson Springs on the historic Pony Express Trail in Utah's west desert.
Police Chief Thayle Nielsen told KSTU-TV that authorities have a "strong interest" in Josh Powell but he did not elaborate. Asst. Police Chief Craig Black did not immediately return a message left Wednesday.
Authorities have provided few details on their investigation into Susan Powell's disappearance, although they have termed it "suspicious." The Powell home was locked when officers initially arrived and they broke in, fearing the family had suffered from carbon monoxide poisoning.
Susan Powell's father, Charles Cox, said police found a wet spot in the home being dried by two fans, but police have declined to comment on that.
Investigators said there were no signs of forced entry at the home and they found Susan Powell's purse and cell phone there.
Susan Powell was last seen by someone other than her husband on Dec. 6 - a family friend who ate dinner with her at the couple's home following church.
Friends and family said it would be out of character for Susan Powell to leave her two children and not contact anyone.