(CNN) -- Brian Laundrie's mother wrote a letter to her son that included references to getting a shovel and burying a body, an attorney representing the parents of Gabby Petito said during a court hearing Tuesday.
The Petitos are suing the Laundries for emotional distress in connection with Gabby's death during a road trip with her betrothed, Brian.
The lawyer for Petito's parents, Patrick Reilly, said during a remote hearing in Sarasota County Circuit Court in Florida that he saw the letter at an FBI regional office and it expressed things "including helping him get out of prison, getting a shovel and some other things."
The envelope containing the letter said "burn after reading" according to Reilly, who said the letter was recovered from Brian Laundrie's backpack when his body was found.
Gabby's remains were found at Wyoming's Bridger-Teton National Forest and her death was ruled a homicide by manual strangulation. Before taking his own life, Brian wrote in a notebook he was responsible for Gabby's death, according to the FBI.
In court Tuesday, a defense attorney for Laundrie's parents said the letter is irrelevant to the lawsuit and they shouldn't have to produce it but also confirmed that the letter exists and that another family attorney has it in their possession.
"This document pre-dates Brian and Gabby's trip so its creation really doesn't have any relation necessarily to the unfortunate events that unfolded thereafter. I know that some of the wording that was used in the letter is unfortunate and might suggest that it has some connection but it doesn't," defense attorney P. Matthew Luka said in court.
Reilly pushed back that the letter is not dated and a jury should decide if it's relevant.
"The language in that letter is damning and that letter has a reference to bringing a shovel and burying a body," Reilly said during the Tuesday hearing.
The attorney for Gabby's family wants to ask Roberta Laundrie about the letter in a deposition, he said.
Judge Danielle Brewer said Tuesday, "I don't see how it wouldn't be relevant to the action."
Plaintiffs will ask again for it as part of the discovery process.
Petito's family attorney referenced the note in a recent court filing requesting additional evidence.
Reilly in his request said, "This request would also include the note that Roberta Laundrie wrote to Brian Laundrie which she offered to bring a shovel to help bury the body. This note was released to the custody of Mr. Bertolino on Friday, June 24, 2022 by the FBI," the court filing said.
Since then, Reilly said he's received letters from the Laundries' counsel threatening to sue him for defamation in response to the request to obtain the original copy of this letter.
The lawsuit filed by Petito's parents alleges outrageous behavior of intentional infliction of emotional distress by Roberta and Christopher Laundrie during the time Gabby was missing. The couple refused to return calls or texts to the Petito family as they were frantically trying to find their daughter, it says.
The Laundries have responded in court filings arguing they had no duty to Petito's family.
The case is scheduled for trial in August.