Part of a state law that protects the confidentiality of state Ethics Board complaints was struck down Wednesday by a federal judge, who granted a motion for summary judgment filed by two whistleblowers who were prosecuted under the obscure statute during a lengthy legal battle with former St. Tammany Parish Coroner Peter Galvan.

Terry and Laura King challenged La. R.S. 42:1141.4 as a violation of their constitutionally guaranteed right to free speech.

After Laura King was fired by Galvan, the couple made complaints about the coroner to a number of agencies, including the Ethics Board, and discussed their allegations with the media.

The couple was charged by a misdemeanor bill of information in September 2011 with breaching the confidentiality of an ethics complaint. The charges were dropped the following June, but the couple filed suit nearly a year ago to challenge the law’s legality.

U.S. District Judge Martin Feldman agreed that the section of the law that was used to prosecute the Kings is too broad. That portion bans any person, aside from the subject of an ethics complaint, from commenting without written permission from the subject. The ban includes the person making the complaint.

Feldman’s ruling does not affect the portion of the law that bans Ethics Board members, the board’s executive secretary and other employees from making public comments about private investigations or private hearings without the subject’s written permission.

Terry King called the decision a “good day for whistleblowers’’ in Louisiana and released the contents of six other ethics complaints, each filed by Louisiana United International, a group based in Slidell. The complaints, signed by LUI member Belinda Parker Brown, are dated from October 2013 until this month.

Five of the six complaints are against St. Tammany Sheriff Jack Strain and ask the Ethics Administration to investigate possible public bid law violations, financial irregularities and voter intimidation.

The other complaint, filed May 8, cites recent media reports about St. Tammany Parish District Attorney Walter Reed’s campaign finance expenditures. The reports raised questions about numerous campaign payments to Reed’s son, Steven Reed, and an ex-girlfriend for work that allegedly was never or poorly done.

Laura King, in a prepared statement, said she and her husband filed their challenge to the ethics law to prevent anyone else from “going through what we went through when we were charged with this ‘crime.’ ” She said the public deserves to know what ethics complaints are about and said she hopes the ruling encourages more people to speak out without fear of reprisal.

“The current environment of exposed public corruption in St. Tammany is no accident,’’ Terry King said in a statement. “It should be recognized that in this case, convicted felon Peter Galvan complained to District Attorney Walter Reed, who is the subject of numerous media reports about unethical behavior. Reed recused himself and had the case placed with (former St. Charles Parish District Attorney) Harry Morel, who is reported to be under investigation by the FBI for corruption, as well. This is an enterprise that relied on government-enforced secrecy and brutal tactics.”

The Coroner’s Office had complained to the St. Tammany Parish District Attorney’s Office about the Kings, but Reed recused himself, as did Louisiana Attorney General Buddy Caldwell. The case was turned over to Morel, then the St. Charles DA, who charged the Kings with five counts each of violating the law.

Galvan resigned from his elected position late last year and pleaded guilty to a single count of conspiracy to commit theft. He is serving a two-year sentence in federal prison.

The state argued that a federal court should not rule on the law’s constitutionality because it is an issue of state sovereignty, but Feldman said the case is not strictly a state matter but involves serious claims under the First and 14th Amendments to the U.S. Constitution.

Feldman also disagreed with the state’s contention that the law is constitutional because it is narrowly tailored and prohibits speech only while ethics investigations remain private.

The state said the plaintiffs were not actually harmed because the charges against them were later dropped and expunged, and it said their claim that they feared future prosecution was “too hypothetical.’’

But Feldman disagreed. “The history of enforcement in this case makes the threat of future prosecution a real possibility,’’ he wrote. “The state’s contention that plaintiffs suffered no actual injury simply because the charges against them were dropped is specious at best.’’

Al Robert, the Kings’ attorney, said he would be surprised if the state appeals the ruling, which he called “by all means proper and correct and grounded in First Amendment principles.’’

Follow Sara Pagones on Twitter at @spagonesadvocat.

Editor’s note: This story was altered on May 15 to reflect the fact that the Kings are not residents of St. Tammany Parish.