Scouts Canada has apologized for trying to sue the elderly parents of a deceased New Brunswick man who said he was sexually abused by his scout leader.

The organization laid the third-party claim after it received notice it was being sued by Gilles DesRoches's estate over the alleged abuse.

DesRoches took his own life in 2014 after years of mental anguish, which his family says was brought on by abuse he said he suffered as a boy in the 1970s.

His widow and daughter vowed to get justice for him. They filed a lawsuit against Scouts Canada in 2015, saying the organization is responsible for the abuse that haunted him until his death.

Gilles DesRoches is pictured here during happier times. His family says he took his own life in 2014 after being haunted by childhood sexual abuse. (CBC)

Scouts Canada responded with a third-party claim against DesRoches's parents, claiming they "had a duty to provide their son with counselling and therapy at the relevant times."

The organization dropped the suit after being contacted by CBC News.

'We are deeply sorry'

The third-party lawsuit was "completely unacceptable," Scouts Canada spokesman John Petitti told CBC News in an email.

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He said the organization ordered its insurer to drop the suit as soon as officials at Scouts Canada learned about it.

"This is not how we treat people," Petitti said.

"Quite simply, it should never have happened and we are deeply sorry that it did."

The organization went a step further on Thursday, sending a letter to families involved in the Scouts across the country.

"I am writing to tell you, without reservation, that this tactic was wrong, it was inexcusable, and I am deeply sorry that it was pursued," says the letter, which is signed by Scouts Canada chairman Jason Anderson.

The apology comes as Scouts Canada tries to rehabilitate its image after a 2011 CBC News investigation found the organization had secret files on suspected pedophiles in its ranks.

Father puzzled by lawsuit

Norm DesRoches couldn't understand why Scouts Canada would want to sue him.

He said he and his wife, Marguerite, put everything they had into trying to save their son, including paying his bills and even moving in with him during the final years of his life.

Norm DesRoches flips through an album of family photos. His son Gilles took his own life in 2014. (CBC)

"You don't sue somebody who doesn't have anything," DesRoches said.

He said Scouts CEO Andrew Price delivered the apology.

But it's not enough, he said, knowing that his 21-year-old granddaughter, Danika, has lost her father.

"She'll be going through her life with no father so ... to me, an apology is not enough."

'Chilling effect'

Some legal observers say third-party claims are being used more often by institutions facing lawsuits over historic sexual abuse.

They're becoming more common because it's become easier to prove institutions are liable, said Toronto lawyer Susan Vella, who has represented sexual abuse victims.

Toronto lawyer Susan Vella, who has represented sexual abuse victims, worries that survivors won't take their cases to the courts if they fear their parents will be sued. (CBC)

She worries the tactic could discourage survivors from bringing their cases to the courts.

"It causes them to feel guilt and shame over something they had absolutely no control over," Vella said.

The DesRoches's lawyer, Robert Talach, has the same concern.

"I wonder aloud if this is to create a chilling effect, to send a message that if you're going to sue us, we're going to sue everyone in your family."

Scouts Canada said that approach is "inconsistent with what we stand for as an organization."

"We have apologized to the family and put processes in place to ensure that this does not happen again," Petitti said.

'It must have been a real nightmare'

Gilles DesRoches spent his life searching for happiness.

On good days, family photos show him swimming and playing with his daughter. But the bad days eventually outnumbered the good ones.

At his home in Miramichi, Norm DesRoches pointed to a picture of his son as a teenager, posing with his mother at a birthday party.

Gilles DesRoches is pictured in photos as a teenager. (CBC)

The photo captures how his son changed. He said his boy's eyes looked empty ever since a camping trip in 1976 when he was 11.

The day he got back from the trip, DesRoches said his son told him his scout leader tried to touch him inappropriately.

Soon after the trip, his son began to drink, a vice that would later take over his life.

"It must have been a real nightmare for him," he said.

DesRoches said he immediately told Scouts Canada about what happened on the trip.

According to the family's statement of claim, Scouts Canada promised to remove the scout leader and prevent him from rejoining the organization.

It would take nearly 40 years before Gilles revealed more about what happened on the camping trip, his father said.

Through tears he told his father that he had been forced to perform oral sex on his scout leader.

On Sept. 21, 2014, his father got a call after Gilles didn't answer a knock at the door of his trailer.

Gilles DesRoches swims with his daughter, Danika. (DesRoches family)

Norm knew his son was gone even before two police officers arrived at his home to tell him Gilles had killed himself.

An unexplained struggle

Gilles hadn't told his wife or daughter about the alleged abuse.

But Joanne Bourque says her late husband got counselling and tried medication. Nothing worked.

"He didn't feel like he deserved to be happy," Bourque said.

Joanne Bourque says she and her daughter filed a lawsuit against Scouts Canada to get justice for her late husband. (CBC)

Marguerite DesRoches learned about the alleged abuse a few days after her son died.

The man accused of abusing him went on to abuse other children after being kicked out of Scouts in New Brunswick, according to the family's statement of claim and supporting documents. He rejoined Scouts in Alberta and was convicted of four sexual abuse charges against boys in his troop, the statement of claim says. For that, he was sentenced to nine months in jail and 18 months' probation. He was then convicted of fondling a boy on a school playground in 1997 and served one year of a 17-month sentence, the documents allege.

'I will get justice'

At a private family burial, Bourque made a promise to her late husband.

"I will get justice," she said. "I'll tell the story."

She said that's why she and daughter Danika decided to sue Scouts Canada.

"I just wanted them to take responsibility for what happened," Bourque said.

The legal filing says the alleged abuser used the power granted to him by Scouts Canada to abuse Gilles.

Scouts Canada, it alleges, also failed to warn families about the risk of sexual abuse, despite knowing its organization had been infiltrated by predators.

Scouts Canada has denied the allegations in a statement of defence. None of those allegations have been tested in court.