SOUTH POINT — The host family of an exchange student missing for nearly three weeks remains hopeful that she will come home, but fears that the teen is in grave danger.

Xinyan Lin, 17, a junior at South Point High School, was last seen getting into a van at the Speedway on Solida Road shortly before 9 a.m. March 3. She took no clothes with her, just her passport, a backpack and about $700 in cash, according to police.

Lin left a note saying that she was going to New York City for a week with a female friend, but would be back, said her host father on the condition of remaining anonymous.

The evening she left, Lin called from New York saying that she was OK and reiterated the fact she was safe and would be back to South Point soon. The week passed and she never came home.

“This was the last thing we expected,” Lin’s host father — her legal guardian — said. “She was a model kid. She was very obedient, totally respectful, just a really good kid.”

She was also very close to the two children in her American family, a 10-year-old boy and his 16-year-old sister.

The last correspondence the family had with Lin was March 13, when a letter arrived from the teen stating that she was going to stay in New York, where she was in a Chinese community where she felt comfortable. In the letter, she also thanked her American family for their hospitality. She left no contact information or any further information concerning her whereabouts.

The letter did not reassure the family, her host father said. In fact, it gave them more questions than answers, especially the strange ending of the letter, he said.

“The end of the letter said ‘Say Bye,’ like someone was standing there telling her what to write. She did not sign her name, it just said that,” he said. “That concerned us.”

Through calling card records, the police have discovered that Lin called her family in China the night before she disappeared and also the Monday after.

“I think this was planned all along. I think it was an act of love from her family to get her out of China, but I still think she is in big time danger. Who knows what kind of people she is up there with or what kind of danger she is in,” her host father said. “They may have found someone to take her up there, but I think it’s a bad situation. I think the only way she is safe is if she is with a family member.”

It is not known if Lin has family members in New York; if she does, she mentioned it to no one.

No members of Lin’s family have contacted the American family, something her host father finds unusual.

If she wanted to come to the United States to escape conditions in China, his family would have helped her, he said; the family would have helped her graduate high school, even college, and would have helped her get the paperwork needed to remain in the country.

“I would have adopted her, that’s how much I thought of her. I would have understood if she wanted to come to the United States. I know how oppressive China is toward women,” her host father said.

Lin had come to the United States in late December for one semester. He said because of her strict, sheltered upbringing in Communist China, he fears she will be taken advantage of or harmed by people who realize she is gullible and vulnerable. He fears Lin may be forced into slavery or prostitution, or worse. He also fears that she may be dead.

Even though she may not have known what she was getting herself into, Lin’s host family believes she left of her own freewill. They do not believe she left the area with someone she met locally because Lin did not like to drive or go out, her host father said, and did not receive phone calls except from relatives in China. Forensics experts have examined the family’s computer and turned up no unusual correspondence.

The Lawrence County Sheriff’s Department, as well as the New York City Police Department and the Federal Bureau of investigation are investigating Lin’s disappearance. Lin’s passport was only valid if she was attending school through the exchange student program, so the Immigration and Customs Enforcement could also be called in on the case.

Disappearances of exchange students are extremely rare, said Dorothy Ledger, regional coordinator with Academic Year in the United States of America, a group that matches foreign students with American host families.

“I’ve never had this happen and I’ve been doing this for six years,” said Ledger, who oversees exchanges students in all counties south of Columbus, as well as Greenup and Lewis counties in Kentucky.

Very few students come from China, she said. In fact, Lin was the only one in her coverage area.

She said there are so many unanswered questions that remain about Lin’s disappearance.

“All we want to know is that she is safe. Just because she left with someone doesn’t mean she went of her own freewill or that she is doing OK,” Ledger said.

Lin’s host father said he know disappearances are rare, but he does know of a similar situation in Huntington, W.Va., last year where a Chinese exchange student came to attend school, but soon after apparently left of her own free will and never returned.

The host father said his family is “numb” about the situation and hopes that good news will be coming soon.

“I think the only way we will find her is police in New York can catch up with her and we doubt that is likely.”

He said the family has come to the realization that there is nothing more they can do to bring Lin home.

“We just have to wait for that phone call that says she is OK.”