The 48-year-old Guelbert was jailed in 1999 for 12 years for raping a 15-year-old girl in Nottinghamshire, but was released on licence in 2008 after being made to sign the Sex Offenders' Register.
He is understood to have moved to Switzerland after that without notifying the authorities about the change of his address, thereby breaching the conditions of his licence.
The Derby Telegraph crime correspondent Shaun Jepson and Nottingham Evening Post photographer Jemma Cox responded to a public appeal by the police to help trace five missing sex offenders. They searched the Facebook to see if anyone from the group was listed on the social networking site.
The journalists discovered that Guelbert had a profile page with Switzerland as his location. They managed to trace his phone number and address in the village of Obermumpf, near Basle and confronted him after informing the cops.
