HILO >> A former Alaska man whose girlfriend was found strangled is missing in Hawaii and his family says he may also have been the victim of violence.

Tom and Kathy Johnson of Petersburg, Alaska, the parents of Boaz "Bo" Johnson, 22, also say their son has been unfairly portrayed as a suspect in the death of Brittany-Jane Royal, 25.

They and another son, Mark, traveled to the Island of Hawaii and hope to find their son alive, they told the Hawaii Tribune Herald. Johnson and Royal had camped near an entry to a lava viewing area in Kalapana, the elder Johnsons said, but information from police has been limited.

"We don’t even know where the tent is located," Tom Johnson said. "They told us that they have had people out there for a few days and searched around maybe six square miles and they had helicopters out there looking for him or any evidence. But as far as anything else, nothing that I can recall."

The Johnsons last spoke to their son on May 27, one day before Royal’s body was found in fishing boat line off the lower coastline of Puna.

Lt. Greg Esteban of the Hilo Criminal Investigations Section said police are pursuing leads in the case but have not found Bo Johnson.

"As a result, he is still considered a missing person and he is not excluded as a suspect in the (homicide) case," he said.

Police photos of the campsite did not look like a crime scene, Kathy Johnson said.

"There was a photo that showed their guitars and ukulele neatly stacked up in the corner of the tent," she said. "If there was a struggle in the tent, they probably should have been knocked around and on the ground."

Police have sent evidence from the campsite to a forensic lab, Estaban said.

The Johnsons met Royal in April in Alaska and learned she was pregnant. The couple then traveled to Tustin, Calif., to see Royal’s parents.

They planned to buy 10 acres of land on the Kalapana lava field to build a home and start an organic farm. Johnson spoke of the plans in his last conversation with his father.

"He was upbeat because he was about to do the most important thing he’d ever done in his life; that was to get that property the next morning," he said.

Johnson didn’t appear for the property appointment. Police issued a bulletin about his disappearance May 30.

One of Johnson’s sisters said her brother had been threatened by a commercial lava tour operator after Johnson took a family out to see lava flows.

"He just showed up at my brother’s house in Kalapana," she said. "He was under the impression that we’d been taking these people out to the lava for pay. He said he owned all 900 acres of the lava, that he owned it and that we weren’t allowed to go out there."

The guide, she said, threatened to shoot up the house if Johnson persisted in giving tours.

Mark Johnson said he wants police to investigate the threats against his brother.

"Whatever channels it takes to go through the legal system, that’s what we’re gonna be willing to do," he said.

Tom Johnson said his son was not involved in Royal’s death.

"He would not do that," he said. "This isn’t just two people who met and camped together one night. They were in love. He loved her and he was looking forward to having that baby and making a life for them out there. That was the most important thing to him."