BELOIT, Ohio - A West Branch Local School District teacher is resigning from his position amid a criminal investigation of an alleged incident involving a former student. 

Nathan Heddleston turned in his letter of resignation on Monday amid an accusation that the teacher had an inappropriate relationship with a former student. 

According to a press release, the West Branch Local School District is continuing to work with local law enforcement agencies and the Alliance Police Department is currently investigating an accusation that the teacher had an inappropriate relationship with a former student. 

The alleged incident happened in July 2015 at a location off of school property, according to a press release from the West Branch School District. 

"The minute this accusation came to light the district began to aggressively act in the best interest of our students, as the safety and welfare of our student population is our top priority," said Tim Saxton, Superintendent of West Branch Local Schools. 

Heddleston's official resignation letter states that he is leaving the school district because of personal reasons.

The West Branch Local School District will hold a Special Board of Education meeting on Monday to accept Heddleston's resignation. 

Heddleston was placed on administrative leave pending the investigation on April 30. 

21 News contacted Heddleston, but he decided not to comment on the pending investigation. 

Saxton said the matter was first brought to his attention on Friday evening through a social media post. 

Saxton said he placed Heddleston on paid leave Tuesday morning.