The Malaysian police on Wednesday said a female suspect has been arrested in connection with the assassination of North Korean authoritarian leader Kim Jong-un’s half brother Kim Jong-nam, BBC reported. A police statement said they identified the suspect based on CCTV footage and that she was in possession of a Vietnamese travel document.

The South Korean government confirmed that Kim Jong-nam had been assassinated and said that its intelligence agency suspected the involvement of North Korea in the murder. Seoul’s legislators said the Kim Jon-un had issued a “standing order” to kill his half-brother, Reuters reported. An assassination attempt in 2012 had failed, they said. South Korea claimed that Kim Jong-nam was living with his second wife in Macau.

US government sources told Reuters that they, too, suspect that North Korean agents were responsible for the assassination. On Tuesday, South Korea’s Yonhap News had reported that Kim Jong-nam was assassinated at the Kuala Lumpur airport on Monday.

Kim Jong-nam, the eldest son of late dictator Kim Jong-il, had challenged his half brother’s succession to the top post. Officials said he had been trying to takeover the reigns of the isolated nation. Jon-nam was living abroad after a reported dispute with his father over his attempt to enter Japan with a fake passport.

He was born from the former leader’s extra-marital relationship with South Korean actress Sung Hae-rim, Yonhap News reported.