This undated photo shows contraband, including strips of Suboxone, smuggled by an undercover investigator into the Rikers Island jail in New York City. (New York City Department of Investigation via AP)

Maryland corrections officials have withdrawn a controversial proposal for the first statewide ban on letters sent to inmates — an attempt to stop smuggling of a difficult-to-detect drug that has become a problem for jails and prisons nationwide.

The state’s Public Safety and Correctional Services Secretary Stephen T. Moyer proposed the ban last month but said Wednesday that he had dropped the request. Lawmakers and civil liberties advocates called the ban an extreme and unconstitutional move that would have deprived inmates of contact with loved ones.

Moyer said he is forming a focus group to study the best ways to block mail smuggling of contraband, including Suboxone, a liquid medication used to treat heroin addiction that also can be used to get high.

Maryland prison officials discovered 1,615 instances of Suboxone being smuggled via the mail last year, and said such attempts are on the rise — part of an ongoing and alarming epidemic of drug addiction that has sent the number of fatal opioid overdoses throughout the state soaring in recent years.

The drug can be soaked into photos and paper that are being put in the mail, or hidden in tiny strips inside envelopes.

“It’s like a Listerine strip,” said Gerard Shields, a spokesman for Moyer, referring to a dissolving breath freshener. “It’s a big problem.”

The ban in Maryland would have been the first adopted by a statewide prison system. The policy would have allowed postcards, and would not have applied to communication from lawyers.

Currently, the jail in Cecil County only allows inmates to receive postcards. Several other local jail systems across the country also have banned letters to inmates. Some of those policies were abandoned, however, after legal challenges.

Sonia Kumar, a staff attorney with the American Civil Liberties Union of Maryland who has spoken to Moyer about the policy, said a better approach would be to focus on training staff to intercept drugs while screening mail.

In another attempt to stem the influx of Suboxone into prisons, Maryland’s Medicaid program in July removed the more easily smuggled film form of the drug from its preferred medication list in favor of tablets.

Prisoners-rights groups have successfully challenged a postcard-only policy on free speech grounds in Spokane, Wash., and reached a settlement with New Hampshire over its policy barring greeting cards and drawings. Utah officials also barred inmates from receiving marker or crayon drawings in a bid to stop Suboxone smuggling.

David Fathi, director of the ACLU National Prison Project, called bans on letters “the latest bad idea” in the corrections world because the bans make it harder for prisoners to reintegrate into society.

“Prisons should be doing everything they can to encourage prisoners to send and receive mail, not setting up these arbitrary barriers,” Fathi said.

He said letters are especially important for the low-income families of inmates who cannot afford phone calls or lengthy or frequent trips to prisons. Postcards, Fathi added, don’t allow for private or in-depth ­communication.

In Maryland, state lawmakers on the Joint Committee on Administrative, Executive and Legislative Review, which needed to approve the letter ban, echoed the ACLU’s concerns.

“We all recognize the serious challenge of preventing contraband from making its way to prisoners,” said state Sen. Roger Manno (D-Montgomery), co-chair of the review committee.

But, he added, it “would be unprecedented to ban all mail going into facilities other than postcards, and it raises serious constitutional concerns.”