BANGOR, Maine — A 53-year-old Maine State Prison inmate who died Saturday morning had sued state correctional officials in federal court in 2007, alleging that his civil rights had been violated.

Deane Brown died while serving a 58-year sentence for multiple robbery, burglary and theft offenses of which he was convicted in 1996 in Knox County Superior Court, Maine Department of Corrections Commissioner Joseph Fitzpatrick said in a news release.

Brown’s earliest possible release date was not until 2032, the commissioner said. In accordance with the department’s policy and Maine attorney general’s office protocols, Maine State Police and the medical examiner have been notified, and they are reviewing the death.

According to published reports and federal court documents, Brown filed a federal lawsuit in 2007 alleging that his First Amendment rights to free speech were violated after he forwarded a letter written by a guard who sympathized with prisoner complaints to a Rockland low-frequency radio station. The letter was posted on the station’s website.

Brown alleged that for nine months in 2006, he regularly telephoned the host of a Saturday morning program who put him on the air to report on problems, as perceived from the prisoner’s perspective, within the facility.

His lawyer said that until then, prison officials did not oppose the regular radio appearances, even though they were largely critical.

After the guard’s letter was made public, prison officials wrote a cease and desist letter to Brown, asserting that prisoners cannot serve as “news correspondents.” Officials then blocked prison phones from being able to call the radio station, and Brown was transferred shortly afterward to a prison in Maryland.

His lawyer argued that existing federal case law establishes the right of prisoners to serve in this role but the case was dismissed in fall 2008.

In an effort to change how prisoner transfers work, Ron Huber of Rockland, host of the show on which Brown appeared, wrote the first draft of LD 690, An Act to Amend the Laws Governing the Transfer of Prisoners to Other States.

When the measure was considered by lawmakers in 2011, Huber said he believed some prisoners were transferred out of state as a form of punishment and that Brown was sent away for being a whistleblower, which corrections officials denied.

The legislation was not adopted, but it did lead to a state policy requiring a plan to return prisoners sent out of state back to Maine, as well as checks and balances for those facing being sent out ot state, according to his obituary.