A bombshell “burn after reading” letter that Brian Laundrie’s mother wrote to her son vowing to help him dispose of a body before he went on a fatal roadtrip with fiancée Gabby Petito has been released to the slain woman’s family.

Petito’s body was discovered on 19 September 2021 in Grand Teton National Park in Wyoming, five minutes from the area the couple’s van had been found after Petito’s parents reported her missing from the couple’s cross-country roadtrip.

Laundrie’s body was discovered in Florida’s Carlton Reserve a month after he was declared a person of interest in Petito’s disappearance – while his family has faced criticism over their response to the high-profile case.

The Petito family has brought an emotional distress lawsuit against the Laundries, with a letter from Roberta Laundrie to her son included in recent evidence in the case.

“If you’re in jail I will bake a cake and put a file in it. If you need to dispose of a body. I will show up with a shovel and garbage bags,” she said in the letter, which was released by the Petitos’ attorney.

“I just want you to remember I will always love you and I know you will always love me. You are my boy. Nothing can make me stop loving you, nothing can or ever will divide us no matter what we do, or where we go, or what we say – we will always love each other.”

Florida Judge Danielle Brewer ruled the letter was admissable evidence in the Petitos’ case this week, prompting its public release by the family.

An attorney for Laundries had argued that the letter should not be used as part of the case, stating that Roberta Laundrie’s “choice of words in hindsight are unfortunate, but that doesn’t mean the letter is relevant”.

Ms Laundrie said that she wrote the letter to her son when the pair were “experiencing a difficult period in our relationship” and said that the language used in the letter pertaining to disposing of a body “were common enough in our circle of friends and family to describe who you could turn to in the most troubling times of your life”.

The Petitos claim in their suit that the Laundries were aware that their son had killed Gabby even as they released a statement saying they hoped she would be found. The Laundrie family deny any knowledge of what had happened and have previously said they believe they “did everything the right way” in the wake of the couple’s disappearance.