The reward for information in the disappearance of a young Butler County woman is now five times larger, at $25,000.

Officials with the local CrimeStoppers organization tell The Cincinnati Enquirer that family and friends of 22-year-old Katelyn Markham have added $20,000 to the $5,000 in reward money that came earlier from an anonymous donor.

Markham was last seen Aug. 13 in Fairfield, a suburb north of Cincinnati. Her fiance reported her missing the following day.

Multiple media outlets report the scores of volunteers looking for Markham are being joined by Tim Miller, the founder of director of Texas EquuSearch. The private group has been involved in several high-profile missing person cases, including the unsolved 2005 disappearance of Alabama teenager Natalee Holloway in Aruba and which recently sued Casey Anthony after searching for her missing daughter, Caylee.

Tim Miller, founder of the search group, said, "The family called, but we never get involved until we talk to law enforcement."

His non-profit organization has been involved in 1,200 missing person cases.

"We've recovered our 129th victim that was deceased. Many of them would have never, ever been found. So, I think we've got the experience, the resources. I think we've got the determination," said Miller.

The search for missing people like Katelyn is personal for Miller. His own daughter, Laura, was kidnapped and murdered in 1984. He is hopeful that something will lead him and his team of volunteers to find Katelyn.

The case has baffled local investigators from the beginning. There were no signs of foul play at Katelyn's townhouse, but authorities said her cell phone was missing and was turned off Sunday morning.

Miller said, "Katelyn's our next search. So let's put all our resources to work and let's hold out that little glimmer of hope that she's alive."