'She's Fighting Like Hell!' Mollie Tibbetts' Brother Shares New Details About Sister

Mollie Tibbetts is alive, says her baby brother, who is convinced the missing Iowa University Student is doing everything in her power to break free from the fiend preventing her from coming home.

As investigators conduct a massive manhunt to search for Mollie, Scott Tibbetts, 17, told RadarOnline.com in an exclusive interview that he and other family members know how determined his big sister must be to return.

"We know how strong she is and how she never gives up in anything she does. I'm sure she's fighting like hell to get back," Scott said.

Mollie, 20, was last seen going for an early-evening jog in her hometown of Brooklyn, Iowa, on July 18. Authorities say she left her boyfriend's home, where she was alone dog-sitting while he was away, and that she has not been seen since. She was reported missing when the second-year psychology major failed to show up at her daycare job the next day.

Her unexplained disappearance shocked Brooklyn, a tiny city buried in the middle of Iowa where volunteers came forward in droves to search for Mollie.

"We're a town of 1,400 people and there were 300 or 400 of us at 5:30 in the morning the day after she went missing to go look for her. That's what it says about our community" her grateful brother told RadarOnline.com.

Scott, who will soon start his senior year at Brooklyn, Guernsey and Malcolm High School, the same school Mollie attended, holds back when asked who he believes is holding his sister against her will and why.

"I don't want to speculate too much on that," he says, even when asked about a hog farmer living in nearby Deer River, who's been questioned by local and state authorities, including the FBI.

He also acknowledged knowledge of sex-traffickers who lure away women and young girls to sell them off as slaves – a theory which is being passed around by local residents to explain Mollie disappearance as RadarOnline.com exclusively reported.

"It's hard to believe, but you never know," he told RadarOnline.com.

Richard Rahn, special agent in charge at the Iowa Department of Public Safety, declined to comment on the theory.

Scott, like his parents Robert and Laura who've made impassioned pleas for Mollie's safe return, asked RadarOnline.com to deliver his own message to her possible abductor.

"You just have to reverse the roles. I'm sure you have a person like Mollie in your life and you have to think about how heat-broken you'd be if you lost her.