The Chicago Sun-Times reports the travels included trips to China, Israel and Korea.
Rutherford is seeking the Republican nomination for Illinois governor. He faces state Sens. Bill Brady and Kirk Dillard and businessman Bruce Rauner in the March 18 primary.
Rutherford is the first state treasurer in at least 24 years to accept third-party funded travel overseas as part of his job.
He defends the trips as appropriate.
Mary Frances Bragiel is a spokeswoman for the treasurer. She says Rutherford took the trips for “educational purposes” and that no taxpayer dollars were used.