A non-profit publication has filed a lawsuit in federal court against the Macomb County Jail claiming jail officials have censored inmate mail through stringent restrictions.

The Prison Legal News (PLN) and its Lake Worth, Fla.-based publisher Human Rights Defense Center say the jail’s policy amounts to censorship by refusing to accept monthly journal and other correspondence delivered to inmate subscribers in the Mount Clemens facility.

The jail’s action violates prisoners’ Constitutional rights, the lawsuit claims.

“Defendants have adopted and implemented mail policies prohibiting delivery of mail from (Prison Legal News) and other senders, failing to provide due process notice and an opportunity to challenge the censorship, and denying senders equal protection as required under the Constitution,” the plaintiff attorneys said in court filings.

According to the lawsuit, filed Tuesday in U.S. District Court in Detroit, the Human Rights Defense Center publishes a soft-cover monthly journal “Prison Legal News: Dedicated to Protecting Human Rights” for inmates to help them understand their legal rights.

Its publications are sent to inmates in more than 2,400 correctional facilities in the country, including the Federal Bureau of Prisons and Michigan Department of Corrections, the suit states.

PLN also distributes dozens of books about the legal system and self-help books of interest to prisoners. The purpose of Prison Legal News is to educate prisoners and the public about the “destructive nature of racism, sexism, and the economic and social costs of prisons to society,”

In the court filings, the defense center says the county jail in August 2013 implemented a postcard-only mail policy that restricted incoming correspondence to metered, 5-inch by 7-inch white postcards.

The jail only permits book orders from one distributor, Amazon Prime, the center says. It also limits magazines to 12 titles including People, Field & Stream, Newsweek, Outside, Time, Money, Reader’s Digest, O the Oprah Magazine, Men’s Fitness Shape, Martha Stewart Living and Parenting.

Prison Legal New is not on the list of approved publications.

Jail officials have said the mail policy is designed to cut down on contraband and reduce the time it takes corrections officers to screen mailings and publications.

Macomb County Sheriff Anthony Wickersham and jail Administrator Michelle Sanborn are named in the suit, which was filed Tuesday.

Department spokesman Lt. John Michalke on Wednesday evening said department has not seen the lawsuit and can’t comment at this time.

The Prison Legal News wants a federal judge to declare the policies as unconstitutional, approve a preliminary and permanent injunction to prevent the jail from continuing its mail policy, and awarding punitive and compensatory damages, along with court costs.

The Associated Press contributed to this report