South Adams Elementary Principal Brian Strauss submitted his resignation, effective immediately, on Wednesday.
"Mr. Strauss informed me that he is under investigation in relation to his previous employment in another county," Superintendent Scott Litwiller said in a statement. "The investigation does not involve his work for or presence in South Adams Schools."
South Adams policy allows the superintendent to accept the resignation on behalf of the school board.
It was the second sudden resignation to rock the South Adams system within the past few weeks. Former Athletic Director Mike Pries resigned August 11. His resignation came amid revelations that Paul David Baker, 48, a friend of Pries, was a SA volunteer girls basketball coach who was required to register as a sexually violent predator had been arrested.
Strauss became the South Adams Elementary principal prior to the 2010-2011 school year, replacing Litwiller when the latter was named superintendent.
Strauss had previously been employed as a teacher by South Central Elementary School in Union Mills in LaPorte County.
The LaPorte prosecutor's office has said it has "no public comment at this time" on the Strauss matter.
The search for a new South Adams Elementary principal reportedly is under way. The South Adams School Board meets next Tuesday.