YEONGJU (South Korea) • Madam Kwon Pil Ju has been desperately trying to teach herself English before she is reunited with a son she sent away almost 40 years ago.

Her son, Mr Adam Crapser, 41, was deported from an immigration detention centre in Washington state because he lacks United States citizenship, even though he has lived in the country since he was three years old, the New York Times reported.

A spokesman for the US Immigration and Customs Enforcement told Associated Press that Mr Crapser, who was accompanied by deportation officers, had landed in Seoul on Thursday. It is not known when he will meet his mother.

Until his fate was reported in a documentary broadcast by South Korea's MBC-TV last year, Madam Kwon did not even know that the son she gave up in 1978 was in the US. As it turned out, the boy she called Shin Song Hyuk was one of 200,000 South Korean children sent abroad for adoption since the end of the Korean War, most of them to the US.

In recent years, however, some have returned to South Korea as adults, reporting adoptions gone wrong. Some of the most wrenching stories have come from those deported back to South Korea. Like Mr Crapser, they were abused or abandoned by their adoptive parents, the New York Times reported.

"I have never imagined that he was having this hard life of his," said Madam Kwon, 61, wiping away tears. "I should have kept him even if we starved together. What I did was an unforgivable sin."

Last year, Madam Kwon received a call from a relative who remembered her son and had watched the television documentary. In it, Mr Crapser called out for his birth mother.

Madam Kwon contacted the documentary's producer, Mr Kim Bo Seul, who arranged a video chat between mother and son, and a DNA test to confirm their relationship.

Mr Crapser, who has a wife, a daughter and two stepdaughters, communicated with Madam Kwon through an interpreter.

Meanwhile, Madam Kwon plans to decorate a small room in her house for her son, according to the New York Times.