Kim Jong Un
North Korean leader Kim Jong Un gives field guidance to the Kangdong Precision Machine Plant in this undated photo released by North Korea's Korean Central News Agency in Pyongyang, Feb. 7, 2017. REUTERS/KCNA

Kim Jong Un's half-brother was reportedly killed this week in Malaysia. Two women poisoned Kim Jong Nam, a 45-year-old who at one point was being groomed to take over North Korea once his father died, Monday at an airport in Kuala Lumpur, according to South Korea's TV Chosun.

Much of what Kim Jong Un does as the current leader of North Korea is shrouded in secrecy, but news about his family increasingly isn't. The announcement of Kim Jong Nam's death comes years after he was discovered trying to enter Japan on a false passport to go to Disney, and this past November rumors spread that the leader's wife was pregnant.

"Kim Jong Un's family consists of several half and step siblings, some born out of wedlock, who have, for the most part, remained out of the public eye. Very little information is known about them, except what exists in scattered reports," the 2013 minute help guide book "Supreme Leader: A Biography of Kim Jong Un" reads. "Looking at a family tree one can see how complex the breakdown actually is, with little to actually determine the state of Kim Jong Un and his relationship with his siblings."

Here's what we know about Kim Jong Un's family, according to BBC News:

His parents: Kim is the son of Kim Jong Il, who was the supreme leader of North Korea between 1994 and 2011, and Ko Yong Hui, a consort. His father died in 2011, and his mother passed away in 2004.

His grandparents: Kim Jong Un's dad was the son of Kim Il Sung, who ruled North Korea between 1948 and 1994, and Kim Jong Suk, who was said to have died after suffering "hardships she had endured during the years as a guerrilla fighter."

His siblings: Kim is related by blood to Kim Jong Chul, a 35-year-old who apparently loves Eric Clapton and was deemed too "effeminate" to take over for his dad, and Kim Yo Jong, who worked in propaganda. In addition to Kim Jong Nam, who died Monday, Kim Jong Un has a half-sister, Kim Sul Song, who at one point worked as a secretary in the government. He is also related to Kim Hye Kyong and Kim Chun Song, according to North Korea Leadership Watch.

His other relatives: Kim Jong Un has at least one nephew, a 21-year-old named Kim Han Sol who recently declared his uncle a "dictator." He is married to Ri Sol Ju, and the couple reportedly has a daughter named Ju-ae.