The mother of Nóra Quoirin has said her family are angry and upset after the Malaysian Attorney General's office made a decision that means there will be no inquest there into her daughter's death.
The 15-year-old disappeared from the Dusun rainforest resort about 70km south of Malaysia's capital, Kuala Lumpur in August.
Her body was found ten days after she went missing, around 2km from the resort.
Speaking to RTÉ News, Meabh Quoirin said they found out about the Attorney General's decision to classify Nóra's death as 'No Further Action' through the media, which was later confirmed by their lawyer in Malaysia.
Ms Quoirin said they are angry and upset at the prospect of fighting even harder when they are already "facing so much pain".
"I feel everyday is really difficult and today is just part of that ongoing battle, but we must do it for Nóra," she said.
She added that the point of a Malaysian inquest was to make available all of the findings that police made in their investigation.
"[We need] to establish how Nóra got to where she was because a post-mortem simply cannot do that and so it really actually relies on those in the domestic country to carry it out," she said.
Ms Quoirin described it as "shocking" the fact that they have heard "nothing" from the Malaysian authorities or investigation teams since they left the country in August.
"Whatever it takes, we will be there to do it" to seek justice for Nóra, she said.
Earlier, Meabh and Sebastien Quoirin said they were "shocked" that there will be no inquest into Nóra's death.
In a statement, the family said that to date, they had not received a full post-mortem report into their daughter's death and "only a brief extract".
"It is moreover utterly unacceptable that we have not received a single update from Malaysia since Nóra's death," the couple said.
Nóra's parents said that they want to stress again that it is crucial for them to understand how their daughter came to be found where she was.
Nóra had special needs and her family has described her as a "vulnerable child" and told RTÉ News recently that they still believe there was a criminal element to her disappearance.
"We strongly refute any conclusion that Nóra was alone for the entire duration of her disappearance," they said in the statement issued through the Lucie Blackman Trust charity.
"We believe it is a democratic human right to seek the truth. We have witnessed how our most vulnerable citizens in this world are all too often ignored and we are now facing considerable prejudice in our search for answers.
"We believe it is a democratic human right to seek the truth. We have witnessed how our most vulnerable citizens in this world are all too often ignored and we are now facing considerable prejudice in our search for answers."
The Quoirins said that they were appealing directly to the highest levels of Malaysian government, as well as the Attorney General's office, to assist in their "quest for the truth".