(CNN) The North Korean diplomat who South Korea's largest newspaper said had been executed by firing squad is alive and in state custody, according to several sources familiar with the situation.

North Korea 's special envoy to the United States, Kim Hyok Chol, is being investigated for his role in the failed Hanoi summit that took place between United States President Donald Trump and North Korean leader Kim Jong Un in February, the sources said.

That meeting, the second between the two leaders, ended abruptly without the two sides reaching a deal.

Kim Jong Un's translator in Hanoi, Sin Hye Yong, also is in custody and under investigation, sources said.

Kim Hyok Chol, North Korea's special representative for US affairs, leaves the Government Guesthouse in Hanoi on February 23.

South Korean newspaper Chosun Ilbo reported Friday that Kim Yong Chol, one of North Korea's most senior officials who had sat in the White House across from President Trump for talks little more than a year ago, had been purged and that Kim Hyok Chol had been executed by firing squad as punishment for the lack of success in Hanoi.

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