As a wrestler, he battled Andre the Giant, Hulk Hogan and Mad Dog Vachon. As a candidate for governor, he clashed with Skip Humphrey and Norm Coleman.

This week, however, Jesse Ventura could face his toughest test yet: proving to a federal jury that he was libeled and slandered by a highly decorated former Navy SEAL who is now dead.

Jury selection begins Tuesday in U.S. District Court in St. Paul over a lawsuit the former governor filed two years ago, claiming that the late Chris Kyle, who served in the SEALs, defamed him in a bestselling book, “American Sniper,” by making up a story about a barroom fight in California. Kyle did not identify Ventura in the book but later named him in radio and television interviews.

It’s an unusual and important case testing the definitions of celebrity and defamation.

“This is one of the most important First Amendment cases in recent Minnesota history,” says Mark Anfinson, an attorney who teaches communications law at the University of St. Thomas and specializes in media issues.

The standards for proving defamation are high, Anfinson said. “He’s got to prove not only that the publication was false and harmed his reputation, but he has also got to prove that it was published with actual malice.”

Several settlement conferences have failed, so a 10-person jury will decide the veracity of the alleged bar fight.

“It was completely fabricated; that’s why we are in court,” Ventura said in a brief telephone conversation last week. Ventura is scheduled to testify, along with his wife, Terry, and adult son, Tyrell, according to documents filed by his attorneys, David B. Olsen, Court Anderson and John Bisanz Jr.

Several former SEALs who were at the bar that night are expected to testify they saw no confrontation, nor did they hear Ventura make the derogatory remarks about SEALs and the U.S. military alleged in Kyle’s book.

Kyle was killed in an unrelated incident, so the defendant is his widow, Taya Kyle, who oversees his estate. Two local First Amendment lawyers, John Borger and Leita Walker, are representing Taya Kyle and are expected to call witnesses who will support her husband’s version of events.

The ‘Sniper’ story

Kyle’s book, “American Sniper: The Autobiography of the Most Lethal Sniper in U.S. Military History,” was published in January 2012 and became a No. 1 New York Times bestseller. He claimed to be the deadliest sniper in U.S. military history, with 160 confirmed kills out of 255 claimed.

The book has been turned into a movie, still in production, directed by Clint Eastwood and starring Bradley Cooper. It is not known if the film includes the barroom incident; a spokesman for Warner Bros., which is releasing the movie, had no comment.

The lawsuit centers on a subchapter on pages 310 to 312, titled “Punching out Scruff Face” and recounts an alleged incident in 2006 at a bar and restaurant in Coronado, Calif., near San Diego.

Kyle wrote that after attending a funeral for a Navy SEAL, a small party went to one of his favorite bars, where there were numerous people including “a celebrity I’ll call Scruff Face … Scruff served in the military; most people seem to believe he was a SEAL.” (Ventura served on the Navy SEAL underwater demolition team during the Vietnam War.)

Kyle claims he went over to introduce himself and say he wanted the other man to meet a young SEAL who had been injured in the Iraq war, but “Scruff acted like he couldn’t be bothered.

“We went back over to our side of the bar and had a few more drinks,” Kyle wrote. “In the meantime, Scruff started running his mouth about the war. … We were only there because [President] Bush wanted to show up his father. We were doing the wrong thing, killing men and women and children and murdering.

“And so on. Scruff said he hates America and that’s why he moved to Baja, Calif.”

Kyle wrote that “the guys were getting upset,” so he walked over and asked Ventura to “cool it,” explaining that his group was in mourning.

“You deserve to lose a few,” Kyle alleged Ventura told him. “Then he bowed up as if to belt me.” Kyle claims he recommended that he and Ventura separate and “go on our way” but Ventura “bowed up” again. “This time he swung.

“I laid him out,” Kyle wrote. “Tables flew. Stuff happened. Scruff Face ended up on the floor. I left. Quickly. I have no way of knowing for sure, but rumor has it he showed up [at a SEALs] graduation with a black eye.”

Suit follows talk shows

On Jan. 4, 2012, while promoting the book on a radio call-in show on Sirius Satellite Radio, Kyle said, “Scruff Face” was his pseudonym for Ventura. Kyle named Ventura again the next day in an interview with Bill O’Reilly on Fox television.

On Jan. 23, 2012, Ventura sued Kyle, claiming that a Google search found “more than 5,300,000 results, including news articles, videos and blogs that repeat the defamatory statements and accusations.” The suit said it seriously injured his reputation and undermined Ventura’s “future opportunities as a political candidate, political communicator, author, speaker, television host and personality.”

About a year later, on Feb. 2, 2013, Kyle was killed at a shooting range in Texas by a 25-year-old former Marine allegedly suffering from post-traumatic stress disorder whom Kyle was trying to mentor.

Ventura continued the lawsuit against Taya Kyle, who oversaw her husband’s estate.

“This is a bizarre situation, given that the author is no longer living,” Jane Kirtley, an attorney and Silha Professor of Media Ethics and Law at the University of Minnesota, wrote in an e-mail to the Star Tribune. “Truth or falsity by itself is not the only issue. Ventura must prove Kyle knew he was writing a lie, or acted recklessly in writing his account.”

Kyle gave a deposition before his death that is expected to be played at the trial.

Ventura’s suit “breaks the cardinal rule of politics and public affairs,” said University of Minnesota Prof. Lawrence Jacobs, “by dragging out an embarrassing episode.”

Jacobs, who has followed Ventura’s career as director of the Center for the Study of Politics and Governance at the U’s Humphrey Institute, said the former governor often attempts things “almost certain to fail or just plain without a reasonable chance of success.’’

“But I have also learned the lesson not to count Jesse out,” Jacobs said. “He is a magician, and whether it is politics, business or his latest TV career, he has consistently surprised us.”