The husband of an Arizona woman who vanished during a hike in a California desert last week said that authorities consider him the prime suspect in her disappearance, but insisted on his innocence — despite flunking a lie detector test, according to a new report.

Barbara Thomas, 69, got separated from her husband, Robert Thomas, on July 12 as the two hiked in the Mojave Desert — where temperatures climbed to more than 100 degrees — about 20 miles north of a freeway that passes through San Bernardino, police said.

She was wearing only a black bikini, red baseball hat and tan hiking boots.

Robert said cops are eyeing him as their main suspect — “because it was just the two of us,” he told Inside Edition on Wednesday.

Robert went for a polygraph test — where authorities told him he was being deceptive — but he claimed he had not had any sleep when he took the test, he said on the program.

He firmly insisted he had nothing to do with his wife’s disappearance.

“She is the love of my life,” Robert told the outlet. “Come home. We’re missing you.”

Robert recalled the last moments he saw his wife. He said on the program that the couple had taken a short ride in their camper when they decided to pull over and go for a two-mile walk to take a look at rock formations. They brought beer and water for their jaunt.

They were heading back to the camper when Barbara started pulling ahead, Robert recalled. He told her he wanted to snap a picture of a rock formation — but once he put his camera away, he spotted his wife turning a corner.

“That’s the last I ever saw of her,” he said on the program.

He didn’t see her around the corner, or back at the couple’s camper, he said.

“I hollered her name and I waved my arms, and I looked around the area and I saw that she wasn’t anywhere around,” he recalled on the program. “She didn’t respond. I got really panicky.”

So he called the cops — and responding sheriff’s deputies, K-9 officers and a helicopter combed the scene, without any luck.

Barbara was still missing on Friday.

“I feel like someone did pick her up because she was wearing a bikini, she had a beer in her hand and she was ahead of me and she had to cross that road,” Robert said in the interview.

“If anyone has her, I would just beg that they would release her, no questions asked,” he added. “I just want her back.”