A Michigan inmate is suing Gov. Rick Snyder and the state over his prison's ban on pornographic materials, claiming he is being subjected to cruel and unusual punishment, the Detroit News reported.

In a handwritten lawsuit filed June 10 in US District Court in Detroit, Kyle Richards said the porn ban has "been used as a method of 'psychological warfare' against prisoners, in order to both destroy the morale of inmates and break the spirit of individuals."

The Macomb County jail where Richards is imprisoned does not allow inmates to possess porn, the newspaper reported.

However, instead of suing the county Richards has sued the state, which does allow inmates in state prisons to possess pornography -- with the exception of material depicting simulated rape, bestiality and sadomasochism, a Department of Corrections spokesman said.

Richards, 21, has been in jail since January and pleaded guilty to charges of bank robbery on Thursday. He will be sentenced in August.