Todd Hoffner, a former head football coach at Minnesota State University, Mankato, has been taken off the university's payroll, effective Wednesday, after he was cleared of two felony child pornography charges last year.

However, a faculty union, called the 'Inter Faculty Organization' (IFO), alleges that Hoffner was instead fired from the university, and it has therefore filed a grievance over his termination.

University spokesman Dan Benson declined to comment on whether Hoffner was fired or has resigned from the university.

Hoffner, 46, was charged with possession of child pornography last August, after university officials found videos of his naked children on his work-issued cellphone when he submitted the instrument to the school for malfunction.

University technicians came across the videos and approached the university officials, who then contacted the police. The MnSCU system prohibits the use of official cellphones or mobile devices for personal reasons.

Hoffner was then placed on administrative leave, pending the investigation.

Later in November, the Blue Earth County District Court Judge Krista Jass cleared him of criminal charges, saying that the videos of his children acting silly after a bath did not relate to child porn.

"It is private, family speech of a most uniquely personal kind which the state can neither inhibit nor sanction," Jass said.

Once he was found not guilty, university officials removed Hoffner as head football coach and posted him as assistant athletic director for facilities development, while suspending him for 20 days without pay for an unspecified reason.

He has attempted to challenge the university's decision through his union, the IFO, which comprises of faculty members from the Minnesota State Colleges and Universities system.

"As with the January 2013 suspension and reassignment of Coach Hoffner, the Inter Faculty Organization immediately grieved the termination. The termination has now been consolidated with the January grievance such that both will be heard by a single arbitrator this summer. We expect Coach Hoffner to prevail," the IFO said.

Meanwhile, Aaron Keen, one of Hoffner's assistants, will be the interim head coach till the university finds an appropriate placement for him.