Story highlights Eric Eugene Hartwell was convicted of raping a child in 1991

Law agencies are working to find Hartwell "as quickly as possible," spokesman says

Hartwell was ordered to serve a lifetime of supervised parole

He cut off his leg monitor and fled previously in 2009, the Justice Department says

A convicted child rapist apparently cut off his ankle monitor and left a Colorado group home where he was serving parole, a state official said.

A fugitive warrant was requested minutes after Eric Eugene Hartwell, 51, walked away from "Independence House" in Denver Friday evening, Colorado Corrections Department spokesman Roger Hudson told CNN Sunday.

Hartwell was convicted of raping a child in 1991 and attempted indecent liberties in 1996, according to the Colorado sex offender registry.

"This is an active investigation of an absconder that we are hoping not to send even farther underground," Hudson said.

The corrections department's fugitive apprehension unit is working with other law enforcement agencies to find Hartwell "as quickly as possible," he said.

Hartwell was sentenced to five years in prison and ordered to serve a lifetime of supervised parole by a federal judge in Texas in March 2010 after he was found guilty of failing to register as a sex offender, according to a U.S. Justice Department news release.

Hartwell was placed in a halfway house in Washington state in March 2009 for failure to register as a sex offender, but after just a week there he cut off his leg monitor and fled to Texas, according to the Justice Department.