Liberty in North Korea Director of Research and Strategy Sokeel Park said the defection of senior North Korean diplomat Thae Yong Ho
was a "unique situation," and could lead to threats of retaliation from North Korea.
"There's been those kind of things that have happened in the past for very high level defectors, assassination attempts and death threats ... there will be protection from the South Korean authorities around this person, especially [in] the short term," Park said.
It was announced on Wednesday that Thae had defected to South Korea, along with his family -- the highest profile diplomatic defection in the country's history.
Thae had been stationed in the United Kingdom but chose to defect to South Korea.
South Korean Unification Ministry spokesman Jeong Joo-hee said on Wednesday the diplomat left for the sake of his family and because he was "tired of Kim Jong Un's regime."
Defector from North Korean elite
As with all high-profile defections, Park said the family of the diplomat still in North Korea could expect to face suspicion and possibly punishment in the future.
"At the very least there's going to be suspicion and more surveillance on those family members. This could include any brothers and sisters of the diplomat who defected, extending to cousins and extended relatives," he said.
Park said the defector Thae was the member of an elite family in North Korea, the son of a high-profile general.
Unusually, Park said the diplomat had been with his entire immediate family overseas when he was posted.
"That's quite rare ... a lot of the time there will be a son or an immediate family member that's still back in North Korea kind of as collateral to make it harder for people to defect," he said.
When asked why Thae may have defected to South Korea, rather than the United Kingdom where he was posted, Park said he may have been offered more incentives.
"Maybe he would have better career prospects, for instance, if he came to South Korea, worked with the national intelligence service ... rather than staying in the United Kingdom," he said.
Hundreds of North Koreans defect
From January to July 814 North Koreans have defected to the South, according to South Korea's Unification Ministry, compared to 705 over the same period in 2015.
Defections are most common among the unemployed and laborers, the Unification Ministry said. Defections from those in managerial positions are relatively rare, with just 480 defecting in the past decade, according to South Korea's government.
Overall, an estimated 1,275 North Koreans defected in 2015, the lowest number since 2002. In the past two decades, defections peaked in 2009, with 2,914.
Among the highest-level defections to date were a former DPRK ambassador to Egypt who defected to the United States in 1997.
North Korea's highest profile defection to date was Hwang Jang Yop, who fled to South Korea also in 1997 after holding high-profile positions in the North Korea's Worker Party.
He was credited with developing the North Korean ideology of "juche," or "self-reliance."