SALT LAKE CITY - Investigators said yesterday that they suspect foul play was involved in the disappearance of a Utah mother of two as they grew increasingly suspicious of her husband after he demonstrated an "unusual lack of cooperation" in the case.

Susan Powell, 28, was reported missing Dec. 7. Her husband, Josh Powell, has not been named a suspect, but authorities are highly interested in him, said West Valley City Assistant Police Chief Craig Black.

"Every lead we've been offered so far would leave us to believe this is out of character [for Susan Powell] and thus suspect foul play is involved," he said.

"Josh's unusual lack of cooperation for a husband looking for his wife with the police department, you know, it certainly causes us to ask questions as to why would he do things to exclude the resources that we can bring to the table to find Susan."

Susan Powell was reported missing when she didn't show up to work and her two children were not dropped off at day care. Josh Powell said 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.

Powell has been uncooperative in providing any details that might explain what happened to his wife, Black said. Among other things, he hasn't specified where he went camping or where he was all day Dec. 7, he said.

"That would be awesome if he would be willing to cooperate on that level and take us to his camp site," Black said.

Powell has told police he went camping in Simpson Springs on the historic Pony Express Trail in Utah's west desert - an area of thousands of square miles - that is now covered in snow.

Josh Powell on Tuesday did provide a DNA sample to police, as did several other family members.

Josh Powell's attorney, Scott Williams, a defense lawyer who often represents high-profile clients, described the DNA testing as routine in such cases.

"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.

Williams disputed the allegations made by police that Josh Powell had been uncooperative.

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.

The family has planned a news conference in the Seattle area today, according to a posting on the Friends and Family of Susan Powell Facebook page.