The father of University of Iowa student Mollie Tibbetts spoke out Monday about his daughter's disappearance saying he believes the 20-year-old is with someone she knows. Tibbetts was reported missing by her family on July 19 after she went for a jog in Brooklyn, Iowa.

"It's totally speculation," Rob Tibbetts told ABC News. "But I do believe that Mollie is with someone who she knows, probably someone who cares about her. But that relationship was misguided, misinterpreted and went wrong, and I think they're in a place with Mollie and don't know how to get themselves out of this horrible situation."

As the reward for information leading to the safe return of Tibbetts reached $277,178, the desperate search for the missing girl continues with her family being optimistic that she is still alive.

"The longer we go without finding Mollie's body," Rob continued, "the more hopeful we are that she's alive somewhere and going through something that she can survive."

Rob has urged anyone with information about his daughter's whereabouts to come forward and also asked anyone who may be with her to "just simply call the authorities and put an end to this."

Police described Tibbetts as a 5-feet-2 inches tall girl, weighing about 120 pounds. The psychology major has brown hair and brown eyes.

Hundreds of people have scoured the area where Tibbetts was last seen but found no trace of her. She left behind her wallet and IDs. Authorities looking for Tibbetts also checked her laptop and online accounts but found no clue that could lead to the rising sophomore's location.

Rob told Fox News that the FBI has more than 20 agents on the ground and is "utilizing resources around the country" in an effort to find his daughter as part of a "very large, aggressive, sophisticated effort."

On Sunday, officials in Iowa said they discovered the body of a white female in her 20s, but it was later revealed that the victim was not Tibbetts. The body was found in Iowa’s rural Lee County, about two hours away from where Tibbetts disappeared last month.

Jake Tibbetts, Mollie's brother, told Fox News earlier this month: “We know she is fighting as hard as anyone to get back home,” he said. “It’s a process and we wish it wasn’t so long, but good things take time, and getting her home will be a really good thing.”

FBI
This is a representational image showing law enforcement personnel including FBI agents near a home in Austin, Texas, March 13, 2018. Reuters/Jon Herskovitz