When starvation hit North Korea, Young Ae Ma watched countrymen who stole corn from fields being shot to death in public executions. On dozens of other occasions she witnessed official killings, including of friends and colleagues, for what seemed to be no reason at all.

A diminutive dancer with striking presence, Ms. Ma worked as a spy for Pyongyang, a job she had no choice but to take. In 1999, during an intelligence gathering expedition to China, she received word that she would be imprisoned or killed if she returned because she had had contact with a businessman who fell out of favor with the regime. Ms. Ma never went back to North Korea. Her son thought she was dead.

She sought refuge in South Korea, entering by plane with a fake Chinese passport. After six months of resettlement education, including lessons in capitalism and South Korean customs, she received a permanent residency card. In Seoul, she settled into a new life, performing with a dance troupe of defectors, remarrying a fellow North Korean and eventually hiring a smuggler to kidnap her son so he could join her in Seoul.

Despite her relative prosperity, Ms. Ma was not satisfied. Seoul, she complained, in its eagerness to improve its relations with its northern neighbor, stifled her desire to speak out against the regime of Kim Jong II.

“They told us not to talk about North Korean civil rights,” Ms. Ma, now 39, said in Korean through a translator. She said she was desperate to let the world know “North Korean human rights is not secure. There is no freedom. The North Korean government contains them because they don’t want them to not have exposure to the outside world.”

In early 2004, Ms. Ma and her husband traveled to America with a performing arts group of North Korean defectors and never used their return tickets.

Now, from her tiny home in northern New Jersey’s Korea Town, Ms. Ma has launched a public campaign to pressure the American government into granting political asylum to her and her family. In doing so, she is providing a rare glimpse into the immigration challenges facing many North Korean defectors who are in the New York area illegally and avoiding the attention of authorities.

It’s an uphill battle. While Washington is eager to provide refuge to North Koreans, particularly outspoken women like Ms. Ma who can shed light on one of the world’s most secretive and feared countries, the likelihood of legal admittance is slim. No North Korean was granted refugee status last year, and just two Koreans of the 31 in removal proceedings who petitioned last year were granted political asylum.

A prime barrier keeping North Korean defectors out of America is that many, like Ms. Ma, first have found refuge in South Korea. According to international law, if a refugee has been firmly resettled, they are no longer eligible to receive refugee status unless they can prove they are being persecuted.

No North Korean refugees were admitted to America last year, according to the Department of State, because none applied. Nor did any political asylum applicants who, as is Ms. Ma’s case, were legally in the country.

A small, clandestine community of North Korean defectors appears to be growing in the New York area. Numbering roughly two dozen, most are illegal immigrants. Some entered America on tourist visas; most paid smugglers to bring them to New York via Canada or Mexico.

A reporter for the Korea Times’ Queens bureau who has covered Ms. Ma’s case closely, Yongil Shin, said he started discovering North Korean defectors settling in New York about two years ago. Since then, he’s interviewed about 20 in the New York area.

The Reverend Young Son, who said he is working with about a dozen North Koreans in the New York area and knows of at least a dozen more, said problems with the government is a main reason for coming to America. “Mostly they believe the South Korean government activity and government policy is anti-America, pro-North Korea,” he said, adding, “Also, they heard the USA has more freedom and is richer than South Korea.”

A spokesman for the South Korean consulate in New York, Suk Woo Kang, denied any mistreatment of North Korean refugees, saying they are treated “like any South Korean” and are granted complete freedom. Indeed, the vast majority of North Koreans, when looking for refuge, choose South Korea. Not only is it conveniently located, there are more opportunities afforded to them than in America, such as financial and employment assistance, and they are already fluent in the language.

Regardless, Ms. Ma’s teenage son attempted to enter America illegally from South Korea. He was apprehended while trying to join her after sneaking across the border with Mexico. He now faces the threat of deportation to South Korea.

It was the latest in a series of harrowing trials for her son, now a New Jersey public school freshman with spiky hair dyed a light orange that never would have been allowed in Pyongyang.

Four years ago, a smuggler snatched him off the street four years ago. The trip to China took 15 days, traveling by train, car, and foot to reach a flooded river marking the border. Then the smuggler rented a fishing boat to get them across. In China, Ms. Ma’s son joined the estimated 10,000 to 500,000 North Koreans living in hiding in a country where the government violates international law by not providing protection and often repatriates them to potential death or torture. He was lucky: His mother provided him a plane ticket out.

Just as he was becoming accustomed to life as a North Korean refugee in Seoul, he suffered another readjustment. His mother left for America and did not come back.

He tried to follow, but was denied a tourist visa. A few months later, Ms. Ma arranged for a Christian missionary to take him to Canada. When he arrived, he was told he was too young to immigrate without family and was sent back.

Next, he bought a ticket to Mexico City. When he arrived at the airport, not speaking Spanish, he just told a cab driver, “hotel.” By good fortune, he said, there were some Koreans there who charged him $2,300 to fly to the border and then smuggled him across with two Mexican men.

Luck was not with him when he crossed: He was detained at Southwest Key, a center for unaccompanied minors caught illegally entering the country and ordered removed in August 2005. His lawyer is appealing that decision with the federal Board of Immigration Appeals.

For now, dressed in slouching military pants, he could pass for any American teenager. While his mother makes ginger tea and shares her fears that the South Korean government would persecute her if she returned, he holes himself up in his room, surfing the Internet, one of many portals to the outside world he never knew existed while he was in North Korea.