The Latvian tourist’s body was found six weeks after she went missing from a retreat in May, 2018.
Her decomposed remains, found hanging from a tree in a remote mangrove forest, were identified by her sister Ilze who runs a beauty business in Cork.
Two men Udayan (27) and Umesh (31) are on trial for the killing who the prosecution say lured Liga to the mangrove forest, drugged her and then sexually assaulted her.
Liga's younger sister Ilze was the first person to take to the witness stand on Wednesday with 103 witnesses expected to be heard in the trial.
She told the court how she and her sister came to Kerala where Liga was to undergo therapy to help treat her depression.
Ilze said Liga went missing on March 14, more than a month after the treatment began after opting out of a yoga class.
Over the next number of weeks Ilze followed up as many leads as she could and made appeals for help in a bid to find her sister.
Weeks later, when police discovered the body Ilze was able to identify her sister’s remains.
Following her appearance in court on Wednesday she told local news outlet Onmanorama: “I felt peaceful because I know that what I am saying is true, and that my sole aim is to get justice for my sister and my family.”
“I have been waiting for this day.” she said.
Ilze also expressed her worry over witnesses in the case after it emerged that police recently arrested a relative of one the accused men for making threats to a witness.
She also criticised early rumours in the case that her sister Liga was a drug addict.
In a separate interview with the Times of India before the trial Ilze said that she was happy with the way in which the investigation was carried out.
“I did have an issue with the police not taking serious action, when she went missing, but never about the investigation into her death.”
“It was done professionally and transparently, and it was my request from the beginning that I wanted an honest inquiry.”
“After looking at all the evidence, I was confident that we have held the right men responsible for my sister's rape and murder.”
“It has been four years since I lost my sister. Neither I nor my family could ever have imagined that we would have to live through such a tragedy.”
“My sister was a young and beautiful woman with a kind heart and witty mind. She was a loving and caring person.”
“The fact that someone had such a wicked heart that they can hurt and kill innocent people is something I never understand.”
“But certainly I have no hate in my heart for people here because I know clearly that is not the doing of all the people, it is the doing of two men.”
The trial is expected to last until 21 June.