The decision means that Doan Thi Huong of Vietnam will remain as the only suspect in the case still behind bars.
Huong was one of two women charged with the February 2017 murder of Kim Jong Nam, an offense punishable by hanging. The other, Indonesian national Siti Aisyah, was freed Monday in a surprise ruling and returned to Indonesia hours later.
Prosecutors did not reveal why they rejected Huong’s appeal but let Aisyah go free.
Huong’s legal team had petitioned prosecutors to release her on the same grounds as Aisyah, arguing it would be unfair to free one of the co-defendants but not the other.
Vietnamese ambassador to Malaysia Lê Quý Quỳnh told CNN that Huong wept and pressed his hands to her forehead after the ruling was announced.
Quỳnh said that the Vietnamese justice minister had sent a letter to Malaysia’s attorney general requesting Huong’s release.
“She’s very nervous. She can’t sleep,” Quỳnh said.
Huong’s lawyer, Hisyam Teh Poh Teik, called the decision not to drop the case “disappointing” in court Thursday.
“The decision not to withdraw does not sit well with our criminal justice system. There is discrimination as the prosecution favors one party to the other,” he said.
“Both presented same defense before this court … The public prosecutor has not acted fairly.”
The trial will continue April 1.
Four North Koreans who fled Malaysia for an unknown destination on the day of the assassination were also charged in absentia with the murder. The international police organization Interpol has issued red notices asking governments around the world to send them back to face trial.
Analysts said if North Korea was behind the killing, Kim Jong Un may have seen his older half-brother as a potential leadership threat — even though their father, former North Korean leader Kim Jong Il, had long discounted Kim Jong Nam as a possible successor.
Kim Jong Nam fell out of favor some two decades ago and lived in self-imposed exile in the Chinese-controlled territory of Macau.
North Korea has consistently denied involvement in the killing, though US, South Korean and Malaysian authorities have said Pyongyang was responsible.
Huong, Aisyah and the four North Koreans were accused of exposing Kim to the VX as he entered an airport in Kuala Lumpur on the outskirts of the Malaysian capital, killing him in minutes. Prosecutors alleged that Huong and Aisyah wiped Kim’s face with the chemical before washing themselves. The North Koreans then promptly left the country.
Lawyers for the two women argued they were duped by the North Korean agents, who tricked them into thinking they were taking part in a reality TV show.
Aisyah told CNN in an interview, Wednesday, that she agreed to take part in the reality TV show as side job to make some extra money. She said she was offered the job by a Malaysian man and ended up earning about $120, but declined to speak at length about the case.
“My message to the other woman workers, please don’t easily trust the others. If you want to do something, you have to understand what is that exactly,” she said.
After Aisyah’s release on Monday, Vietnamese authorities appeared to step up their own efforts to free Huong.
Foreign Minister Pham Binh Minh urged his Malaysian counterpart Tuesday to “ensure fair judgement for Huong & to set her free,” according to an image tweeted by his ministry.
Vietnamese authorities had been tight-lipped about the case. They did not disclose whether Huong’s detention was discussed during Kim Jong Un’s visit last month to Hanoi, where he met US President Donald Trump and Vietnamese leaders.
Those meetings would have been unthinkable back in 2017, when Kim Jong Nam’s assassination was widely seen as evidence of his half-brother’s brutal but calculating leadership style. It was not until the following year that Kim Jong Un made a dramatic foray into diplomacy, holding his first historic summit with Trump in Singapore and also meeting the leaders of South Korea and China.