Investigators in Iowa have found the body of a young white woman in her 20s, but they do not think it's the missing college student, Mollie Tibbetts. The unidentified woman's remains were discovered in Lee County, about 100 miles southeast of the town of Brooklyn, where Tibbetts vanished 19 days ago.

Law enforcement is looking into more than 200 anonymous tips. There's even an app for the public to submit tips anonymously, and police say they've chased down hundreds of leads, reports Adriana Diaz.

The reward in the case is now up to $260,000.

Investigators have repeatedly searched fields and hog farms in Deep River, Iowa, but refuse to say why. The area is about a 20-minute drive from Brooklyn, where Tibbetts was last seen jogging July 18.

The search continues for 20-year-old missing Iowa college student Mollie Tibbetts. KCCI-TV

"As leads come in, and information is evaluated, the investigative team responds to those and prioritizes those," said Kevin Winker with the Iowa Department of Public Safety. "I would expect those searches to continue."

Farm owner Wayne Cheney says he was questioned at least two times by investigators. He told Fox News he even allowed them to search his property and cellphone, but turned down their request to take a polygraph test.

CBS News has been unable to reach Cheney, who has several convictions for stalking, harassment, trespassing, and violating orders of protection, according to Iowa court records. Charges in seven other cases have been dismissed.

Cheney told a local reporter last week he doesn't know Tibbetts. "I don't even remember what they asked me. It was a waste of my time, I know that," he told NBC's Des Moines affiliate WHO.

Winkler said, "We're not in a position to say who is a suspect, who isn't a suspect, or that there are suspects."

Winker also wouldn't confirm reports that a red shirt has been recovered, the same color as the one Tibbetts wore to work.

On Sunday, his agency announced the discovery of the body of a young woman in Lee County, Iowa, but say they have no reason to believe that the body is that of Mollie Tibbetts.

Mollie's father, Robert Tibbetts, said, "Time is compressed. Days seem like weeks. We are all trying to bring Mollie back."

Police have also been warning about the spread of misinformation on the internet. Communities of amateur online sleuths have sprung up, scrutinizing every piece of information released so far.

There are at least 10 such groups on Facebook, the largest of which has more than 12,000 members.