SEOUL (NYTimes, AFP) - Until April, Im Ji Hyun had been a modest television celebrity in South Korea, talking to the audience about the country she knew best: North Korea. She even had her own online fan club, indicating that she was among the relatively few North Korean defectors who had successfully adjusted to life in the capitalist South.

This week, Im resurfaced in North Korea, tearfully recalling a terrible life in the South.

"Every single day of my life in the South was a hell," Im, 26, said in a videotaped interview uploaded on the North Korean government-run propaganda website Uriminzokkiri. "When I was alone in a dark, cold room, I was heartbroken and I wept every day, missing my fatherland and my parents back home."

Im - or Jeon Hye Sung, as she was called in the North - said she returned to "the bosom of the fatherland" last month and was now living with her parents in her home town.

She did not reveal how she travelled back to the North. The Unification Ministry, the South Korean government agency that handles issues related to defectors, said it was investigating Im's case.

In her latest TV appearance on North Korean state media, Im accused a South Korean TV station of pushing her to lie about her life in the North to make it sound more miserable than it actually was.

"Everything I said on TV was scripted ... to make North Koreans look barbaric, ignorant and stupid," she said, describing herself as "human trash".

Seoul police sources who probed Im's home and financial accounts in Seoul told the South's JoongAng Ilbo daily there was little sign of her trying to wrap up her life in the country and move elsewhere.

"Relevant authorities are investigating the North Korean defector Im Ji Hyun," said Lee Yoo Jin, deputy spokeswoman of Seoul's unification ministry handling North Korea affairs. Seoul's spy agency declined to comment.

Some North Korean defectors speculated she was abducted by North Korean agents on the China-North Korean border while attempting to help her family members flee their country, reported Korea Times.

The Uriminzokkiri video features another former North Korean defector, Mr Kim Man Bok, who returned to the North two years ago. He joined Im in criticising the South, saying: "The anti-DPRK TV programmes are filled with lies from beginning to end."

Since a famine struck their country in the late 1990s, more than 30,000 North Koreans have defected to the South. The North has tightened border security since young leader Kim Jong Un took power in 2011, sharply reducing the number of defectors and increasing the cost of hiring brokers.

After an extensive debriefing, they go through a months-long programme intended to help them integrate into South Korean society. But they often find it hard to make the transition from the North's highly regimented totalitarian system to the South's fast-paced, hyper-competitive capitalist society.

South Korean officials agree that some of the North Koreans may have returned out of desperation after failing to adjust to life in the South. But they also suspect that some were abducted back to the North after they were lured to China.

Im arrived in South Korea in 2014. From December, she had been among scores of mostly young female North Korean defectors trying to build careers on cable TV talk or reality shows.

While pursing her TV career, she lived in a small one-room studio in Seoul. In her fan blog in March, she said she got busier because she just enrolled in a school, according to the South Korean daily JoongAng Ilbo.

In April, she thanked her fans for a birthday party, calling it "possibly the happiest birthday of my life". Soon afterwards, she disappeared.

Lee So Yool, another North Korean defector and TV celebrity in Seoul, however said Lim would have been broadcast criticising the South regardless of whether she had returned to the North voluntarily or forcibly.

"She has to do it once she is back in the North. She has no choice in order to survive," Lee said during a live Youtube broadcast on Monday.

Lee said the North Korea-themed TV shows aired on South Korean TV - including ones that featured Lim - are hated by the Pyongyang regime for freely discussing issues that are taboos in the North.

"These TV shows let the refugees freely talk about things including the luxurious lifestyle of the ruling Kim family - which is totally banned in the North," Lee said.