Missing Utah mom SUSAN POWELL was murdered by her husband – who poi­soned her food the night before she disappeared!

That’s the heartbreaking theory of Susan’s family members, who believe Josh Powell killed his beautiful young wife in cold blood.

“We know, without a doubt, that Josh killed Susan,” her older sister Denise Cox told The ENQUIRER. “It was a cold, premeditated murder.

“Before she went missing, she told me that Josh cooked dinner for the family. I didn’t think much of it at the time, but he never did that.

“He believed women are inferior and should always be the ones to cook and clean.

“Josh knew a lot about poisons, and we’re convinced that he put something lethal in Susan’s food.”

Powell claimed he left Susan, 28, at home in West Valley City, Utah, on the night of Dec. 6, 2009, while he took their sons Charlie and Braden, then 4 and 2, on an overnight camping trip in freezing weather.

The Cox family believes that after Powell poisoned Susan, he hurriedly dumped her body during the camp­ing trip.

Then he returned the next day to get rid of her body for good, likely throwing it into one of hundreds of abandoned mine shafts in the area.

Heartbroken Denise told The ENQUIRER: ““Police say they are still looking for Susan. We would love to find her body to give her a decent burial and get some closure. Then we could put all this behind us. But this nightmare may never end.”

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