The lawsuit over who wrote the script for the 2012 Warner Bros. film “Trouble with the Curve” is getting personal.

The studio and its high-profile attorney Daniel Petrocelli are now attacking the credibility of an expert in the case, a former U.S. Secret Service agent named Larry Stewart, who generated headlines for his testimony during the 2003 federal prosecution of domestic diva Martha Stewart. As a result, Larry Stewart tells FOX Business he is weighing a defamation suit against the studio for statements it has made about his work in the Martha Stewart case.

The brouhaha involves a 2013 lawsuit filed in the U.S. District Court for the Central District of California by a film maker, Ryan Brooks, against Warner Bros., alleging that the studio stole several scripts that his Brooklyn-based production company had authored in the creation of the movie, starring Clint Eastwood and Amy Adams.

Brooks alleges that Warner Bros. falsified physical evidence in the case to make it appear that the script was written in the late 1990s, which would have been before Brooks copyrighted his material in 2006.

Enter Larry Stewart (no relation to Martha), who completed an analysis on behalf of Brooks’ legal team that he says shows the studio’s documents are fraudulent, thus supporting Brooks’ assertion that Warner Bros. used his material in the making of the movie.

With that, lawyers for Warner Bros., including Petrocelli, then turned back the clock to Larry Stewart’s involvement in the Martha Stewart case; Stewart was the government’s ink expert who cast doubt on Martha Stewart’s defense that she had a pre-existing sell order on shares of a stock that ultimately led to her prosecution for obstruction of justice and later a short stay in a federal jail.

Warner Bros. has argued in court documents that Stewart's analysis shouldn’t be taken seriously since he “has been roundly criticized by courts for manipulating evidence and giving useless, misleading’ opinions,” and was ultimately charged with perjury over the tests he completed in the Martha Stewart case.

But Larry Stewart tells FOX Business that Petrocelli and Warner Bros. have left out a key fact in their argument — that a jury eventually found he was not guilty.

“This is the unfortunate side of the forensic world,” Larry Stewart said in a telephone interview. “If you can’t attack the science you attack the expert.” He says Warner Bros. hasn’t released its own examination of his work, and is relying on smear tactics instead of science to “make me go away.”

As a result, he is considering legal action against the studio. “I’m talking to my attorneys,” he said. “There’s an element of libel when you do something like this.”

Petrocelli didn’t return calls for comment. Warner Bros., through a spokesman, wouldn’t comment on the possibility of Stewart suing the studio, but called Brooks' lawsuit “reckless and a waste of time and money. The allegations are false.”

The next court briefing is scheduled for February 24.

Follow Julie VerHage on Twitter @julieverhage.

Charles Gasparino joined FOX Business Network (FBN) in February 2010 as Senior Correspondent.