It has emerged that Choe Ryong-hae, a top aide to North Korean leader Kim Jong-un, may be related to the ruling Kim family.South Korean news outlet YTN reported Friday, quoting a high-ranking North Korean defector, that Choe is the father-in law to Kim Jong-un's younger sister Kim Yeo-jong.There was speculation that Choe would be victim of a purge by Kim, given his recent disappearance from public view, but according to reports Thursday, he has been sent to the north's top school for re-education.Reports on Kim Yeo-jong's marriage with Choe's second son have been circulating since early this year,but the validity of those reports has been denied by South Korean government sources.