Two years after North Korean leader Kim Jong-un's half-brother was killed, a Malaysian court on Monday told the only remaining suspect in custody that she would not face a murder charge, perhaps signalling the end of a case that had sparked international intrigue.

The move to reduce the charge against the Vietnamese woman Doan Thi Huong came three weeks after an even more stunning development in the case, when prosecutors unexpectedly dropped the murder charge against Huong's Indonesian co-defendant and immediately freed her.

The two women had been the only suspects in custody after four North Korean suspects fled Malaysia following the killing of Kim Jong-nam in a Kuala Lumpur airport terminal on the morning of Feb. 13, 2017.

Oh Ei Sun, a senior fellow with the Singapore Institute of International Affairs, said the decision not to charge the two women with murder likely marked the end of the case.

"This is pretty much the end as the real culprits are apparently hiding behind the veil of diplomatic immunity and state-sponsored sanctuary," Oh said.

Huong and the Indonesian woman, Siti Aisyah, have said they thought they were participating in a prank for a TV show and did not know they actually had been taking part in a high-profile murder. The two were arrested and accused of smearing VX nerve agent on Kim's face.

Kim was the eldest son in the current generation of North Korea's ruling family. He had been living abroad for years but could have been seen as a threat to Kim Jong-un's rule.

Lawyers for the women have previously said they were pawns in a political assassination with clear links to the North Korean Embassy in Kuala Lumpur, and that the prosecution failed to show the women had any intention to kill. Intent to kill is crucial to a murder charge under Malaysian law.

Malaysian officials have never officially accused North Korea and have made it clear they don't want the trial politicized.

The murder charge that Huong had faced carried the death penalty if she was convicted. Huong nodded Monday as a translator read the new charge to her: voluntarily causing injury with a dangerous weapon, VX nerve agent.

Oh said he believed it was a "friendly gesture to Vietnam while paying due respect to the judicial process." While Huong may not have had any premeditated intent to kill Kim, she did apply the VX on his face and has to account for it, he said.

North Koreans never apprehended

High Court Judge Azmi Ariffin sentenced Huong to three years and four months in prison from the day she was arrested on Feb. 15, 2017. Huong's lawyer, Hisyam Teh Poh Teik, said his client is expected to be freed by the first week of May, after a one-third reduction in her sentence for good behaviour.

"I am happy," Huong, 30, told reporters as she left the courtroom, adding that she thought it was a fair outcome.

While handing out a jail term short of the maximum 10 years the new charge carried, the judge told Huong she was "very, very lucky" and wished her "all the best." Vietnamese officials in the courtroom cheered when the decision was announced.

The move follows the Malaysian attorney general's decision to drop the murder case against Aisyah on March 11 following high-level lobbying from Indonesia's government. Huong sought to be acquitted after Aisyah was freed, but prosecutors rejected her request.

Prosecutor Iskandar Ahmad told the court that the attorney general offered the reduced charge to Huong following pleas from the Vietnamese government and her lawyers.

The original charge had alleged that the two women colluded with four North Koreans to murder Kim with VX nerve agent as he was passing through the airport.

Siti Aisyah, the Indonesian defendant, is shown in Jakarta holding a news conference on March 11 after being cleared of charges. (Willy Kurniawan/Reuters)

A High Court judge last August found there was enough evidence to infer that Aisyah, Huong and the four North Koreans engaged in a "well-planned conspiracy" to kill Kim and called on the two women to present their defence.

Huong's lawyer told the court Monday that her guilty plea to the lesser charge showed she "has taken responsibility" for her actions. In asking for a lenient sentence, he also told the court that her move saved judicial time.

Hisyam had urged the judge to take into account Huong's honesty, her acceptance of responsibility and the acquittal of her co-defendant. "She is neither a criminal nor has the propensity to commit a crime," the lawyer said.

Huong, the youngest of five children, has a promising future with a degree in accounting, but she is also "naive and gullible," he said.

Hisyam said the four North Korean suspects, who left Malaysia shortly after the incident and are still at large, were the "real assassins."

They "exploited her weakness and manipulated her to carry out their evil designs under the camouflage of funny videos and pranks," he said.

The judge said he took into account the gravity of the offence and also the fact that Huong was remorseful and a first offender. He said the sentence "would serve the interest of justice."