Kavanaugh's mother, Kathi Craig and her stepfather, Malcolm Hopwood, say the level of "vitriol, hate and accusation" towards their daughter had made her feel so vulnerable she did not return for a scheduled concert this month.
“We fear we’ll never see our daughter here again.”
She was "devastated by the onslaught of hate mail, threats to her safety and is afraid for her life", they said in a statement to media this morning titled "No bonds of love for Marla Kavanaugh".
"Despite the positive reception she received from the crowd in the stand and New Zealanders at the after-match function, more than 50,000 Kiwis, in the privacy of their own homes, attacked her performance," the statement read.
"Over the days that followed they continued to attack her personally, her family and then went on to threaten her life and her safety on Facebook, Tic Toc [sic], Instagram and other social media outlets."
Just over a fortnight on, extreme messages continued to be received.
"These people totally ignored the message and instead attacked the messenger," they said.
They were hoping Kavanaugh, who regularly came home, would return for a concert with her mother in the Cathedral of the Holy Spirit in Palmerston North on August 3, but "she is devastated by the onslaught of hate mail, threats to her safety and is afraid for her life".
The Palmerston North concert has been postponed and Marla, at this stage, feels so vulnerable she can’t return to New Zealand.
In addition to social media, New Zealand newspapers and radio chose to publicise the criticisms and personal attacks, "even to the extent of running a poll", they said.
The were particularly concerned about a comment on TV3’s Seven Days where Kavanaugh was described as “Dunedin’s most well-known murderer”.
“We are devastated at the reaction which went far beyond expressions of opinion about her classical voice, but instead entered the realm of vitriol, hate and accusation,” they said. “We fear we’ll never see our daughter here again.”
“She’s a proud New Zealander and loved returning home for concerts and charity work here often with her twin-sister, Marissa,” Craig said.
Hopwood, a former newspaper editor and university lecturer in journalism, said he was "ashamed of members of his profession who highlighted the polls knowing the hurt it would cause".
Mr Hopwood said he had laid a complaint with Discovery regarding the Seven Days programme, and would be referring it also to the New Zealand Broadcasting Standards Authority.
“There is a duty of care from those people who monitor social media, TV3 and New Zealand Rugby who engaged her and then sat back and let events unfold.
“Until Megan Alatini, who we so appreciate, spoke up about the impact that unnamed personal attacks can have on people in the public eye, no-one sought to align themselves with her and what she was going through,” Craig said.
“As a mother I feel for my daughter and the pain and hurt she is experiencing from people who wouldn’t put their name to such loathsome comments.”
Hopwood said he hoped the NZRU would play a soundtrack of the anthem at All Blacks vs Argentina match at Wellington on Saturday "so the bloodletting doesn’t happen again and people can concentrate on the words".
A New Zealand Rugby spokeswoman today said they had reached out to Ms Kavanaugh to offer their support and thank her for being involved in the San Diego test.
"NZR also stands firmly against abuse of any kind, it does not meet the values of rugby.
"We urge all rugby fans, regardless of their level of involvement in the game, to actively oppose and speak out against anti-social behaviour."
A spokeswoman for Warner Bros. Discovery, which owns TV3, said 7 Days was a comedy show which discussed the previous week’s topical affairs.
‘‘In the week this episode aired, Ms Kavanaugh’s performance was discussed at length across multiple media platforms.
‘‘While panellists take part in this show and express personal opinions, we assessed it to be unlikely the general public would have interpreted Mr Smith’s comments as an accusation that Ms Kavanaugh is a murderer.
‘‘Three does not condone hate speech or threats to individual safety, and we wish Ms. Kavanaugh all the best in her career,’’ the spokeswoman said.