One of the 16 people sought for questioning in an alleged terror plot in Boston has been in federal custody for more than two months and has no terrorist connection, the FBI said Saturday.

In an announcement posted on the FBI Internet site, officials said that Mei Xia Dong (search), a Chinese woman, has been at a Homeland Security Department (search) immigration detention facility in San Diego since Nov. 11.

The match was made soon after her name surfaced last week as part of an anonymous tip about the possible terror plot. The original information indicated that Dong was a 21-year-old man.

Investigators say Dong paid a human smuggler to enter the United States through Mexico and that she came to this country only for economic reasons.

Authorities are continuing to search for 12 other Chinese, two unnamed Iraqis and one Hispanic man who may have been part of the same group. But no evidence of terror motives has surfaced, as the tipster claimed.

"We're going to investigate it to its logical conclusion, but to date there's no corroboration of the original claim," FBI spokesman Joe Parris said.

One leading theory in the case is that the motive for the tip came from the smuggler to exact revenge on the group, perhaps because members failed to pay. Officials have stressed since news of the tip first broke on Wednesday that they doubted the credibility of the terror claims.

The tip included names and photographs of four Chinese people, and the names, some passport numbers and possible birthdates for nine other Chinese — Dong was part of this group — and the Hispanic man.

Government officials have provided no information about the two Iraqis by government officials.

In addition, the tipster claimed that members of the group had talked about material supposedly called a "nuclear oxide" (search) that would follow them from Mexico to Boston. The implication was that the group was plotting to detonate a radioactive "dirty bomb" (search) that spews hazardous material and can sicken or kill people.

No evidence has been found for such a plot.