Governor Deval Patrick’s administration told a local website operator he could face jail time for publishing information that the state provided under an open-records request.

It is unclear whether officials would or could follow through with the threat to Michael Morisy, cofounder of MuckRock (muckrock.com), a website devoted to open records. But the unusual letter, also published on the website, has forced him to consult with an attorney.

The data, which Morisy had not removed from his website by last night, show how much money in food stamps has been spent at businesses around the state over the past five years under the federal Supplemental Nutrition Assistance Program. The state said the information was released erroneously and in violation of federal law.

The statistics from five years identify individual businesses — such as 7-11 branches, Whole Foods outlets, and White Pantry stores — but do not identify food-stamp recipients. The records show that federal reimbursements for food stamps in Massachusetts more than doubled to $559 million between 2006 and 2009 as the economy faltered.

Morisy said he requested the report in June and received it in two batches in July. He published spreadsheets and some original analysis last month.

He noted in his online article that the state’s Department of Transitional Assistance had been particularly helpful in fulfilling his open-records request.

But on Monday, the department sent him a letter explaining that it had provided the data in error and that “failure to remove this information may result in fines or imprisonment’’ of up to $1,000 or one year.

“I was surprised, especially given how helpful they were to begin with,’’ Morisy said. “I’d never heard of a case where information released under a Freedom of Information request was then ordered to be taken down.’’

Koren Christensen, acting general counsel for the Department of Transitional Assistance and author of the letter to Morisy, said she was alerted by federal officials that the information was not supposed to be public. She said she was not trying to threaten Morisy but wanted him to know the potential ramifications, as told to her by the US Department of Agriculture.

“I don’t think it’s going to get to that point, but obviously they took it seriously enough to tell us this,’’ Christensen said. She said her office should have known the information was not supposed to be public: “Our bad.’’

But the American Civil Liberties Union of Massachusetts said the state holds legal responsibility for releasing the information and that demanding that someone who obtained it legally to take it down raises significant First Amendment issues.

“I don’t know how you can unpublish it,’’ said John Reinstein, legal director for the Massachusetts ACLU. “The problem is that the Department of Transitional Assistance has let the genie out of the bottle, and they can’t undo it.’’

The Supplemental Nutrition Assistance Program is managed by the US Department of Agriculture’s Food and Nutrition Service.

Two Agriculture Department officials were unable to answer questions yesterday about why the type of information published on MuckRock cannot be released. But the department did release a statement that implies the state was not told to demand the data’s return from Morisy, but to refuse to release similar information in the future.

“The state erroneously released this information,’’ the statement read. “It is restricted by law. When [the Food and Nutrition Service] found out about the data release, the state was notified that they needed to discontinue releasing data and provided them with the relevant policy.’’

Morisy said that local attorney Rob Bertsche has agreed to take his case for free. Bertsche declined to comment.

Noah Bierman can be reached at nbierman@globe.com.

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