A former NSW teacher has been charged over the alleged historic sexual assaults of a student in NSW's Murrumbidgee region.

Detectives in 2017 began an investigation following reports a girl had been sexually assaulted by a man who was known to her in the 1990s.

Following inquiries, a 54-year-old man was arrested about 8.20am on Tuesday after a vehicle stop north of Dubbo.

He was charged with 10 counts of sexual intercourse - person between 10 and 16 years - under authority.

Police will allege in court the man sexually assaulted the girl, then aged between 13 and 16 and the man's student at a school in Hillston, at various locations in the Murrumbidgee area between 1993 and 1996.

He was granted strict conditional bail and is due to appear before Griffith Local Court in June.

AAP