BUTLER COUNTY, Kan. -

Butler County Sheriff Kelly Herzet said at a press conference Thursday the reward to help find Adam Herrman has been increased to $100,000.

The previous reward being offered was $50,000, but Herzet says an anonymous donor has given more money. He says there are several new leads in the investigation, and he hopes the increase will coax someone to come forward with new information.

July 1 marks the 15th anniversary of the disappearance of Adam Herrman. The 12-year-old went missing from his adopted family's home in Towanda, Kansas in 1999.

At that time, Adam was 4 ft. 4 in. tall and weighed 67 pounds. The National Center for Exploited and Missing Children says Adam had numerous scars on his abdomen, a scar on his left thigh and a birthmark on his lower back. NCMEC has since released an age progression of Adam who would now be 26 years old.

Eyewitness News Anchor Michael Schwanke spoke to Adam's adopted father, Doug Herrman, in February. It was the first time he had ever done an interview on television.

Full Interview: Doug Herrman

Doug said Adam had run away from home. He said he and his wife, Valerie, should have reported Adam's disappearance sooner. Instead, the couple collected $15,000 in payments from SRS for two years after they say they last saw Adam.

In 2011, a judge sentenced the Herrmans to a total of 16 months in prison for welfare fraud.

The Herrman family, including Adam's biological brother and sister, now both in their 20s, live in Oklahoma. Still, Adam remains missing.

Herzet says he does not believe Herrman is still alive, but authorities are still investigating.
 
Anyone with information about Adam's whereabouts or his disappearance is asked to call 1-800-THE-LOST (1-800-843-5678) or 316-322-4257.