The investigation and aftermath into last week’s assassination of the half-brother of North Korean leader, Kim Jong-nam, has undertaken two major developments in the past 24 hours.

Early on Friday afternoon, local time, officials announced that a toxicology report confirmed that Mr Kim had been killed by a VX Nerve Agent, this particular strain is the most potent of all nerve agents.

The XV Nerve Agent is classified by the United Nations as a Weapon of Mass Destruction.

Malaysia’s police chief, Khalid Abu Bakar has admitted concerns over how the substance could have entered Malaysia, adding, “If the amount of the chemical brought in was small, it would be difficult for us to detect,” Bakar said, speaking to Reuters.

Mr Kim was attacked at Kuala Lumpur Airport on 13 February, by two women, who attacked Mr Kim from behind and, “covered his face with a cloth laced with a liquid,” according to a BBC report and video surveillance. He died on the way to the local hospital shortly afterwards.

It is believed, that the two woman who attacked Kim were working under the instructions of four other men, North Korean nationals who later returned to Pyongyang. North Korea has vehemently denied this suggestion by the Malaysian authorities.

Although Malaysia haven’t formally accused the DPRK of the assassination, but they have said North Korean nationals were clearly behind it.

There are currently up to 11 suspects wanted for questioning in relation to the attack, and three, including the two women are already in custody.

Even after a week following his death, Mr Kim’s body remains in a Malaysian mortuary, as no next of kin have come forward to claim the body and a diplomatic dispute has broken out.

The North Korean authorities have vehemently opposed any post-mortem examination since Mr Kim’s death, and have since accused Malaysia of having “sinister” purposes.

The North Korean state run news agency, KCNA, released a report, which accused Malaysia of breaking international law by conducting autopsies on a person bearing a diplomatic passport.

The report was also critical of Malaysia’s response to Kim’s death and believes that their initial conclusion, that Kim was poisoned came, “with the anti-DPRK conspiratorial racket launched by the South Korean authorities,” the report said.

“The biggest responsibility for his death rests with the Government of Malaysia, as the citizen of the DPRK died in its land,” the report added.

Kim Jong-nam’s death is the third death in the immediate family of North Korean dictator, Kim Jong-un, who has already ordered the execution of an aunt and uncle since he succeeded his father, Kim Jong-il in 2011.