Senator Hillary Rodham Clinton’s presidential campaign returned $7,000 in donations last spring that were linked to a fund-raising event in Chinatown in New York City, campaign officials said yesterday, acknowledging another instance where questionable donors came into Mrs. Clinton’s political orbit.

But unlike Mrs. Clinton’s trouble with the former fund-raiser Norman Hsu — whose extensive legal problems and dubious fund-raising practices came as a surprise — her campaign identified the concerns about the Chinatown fund-raising on its own, campaign officials said.

The Los Angeles Times reported yesterday that it had reviewed the cases of more than 150 donors apparently linked to the Chinatown event or to Chinese neighborhoods, and that dozens of donors could not be found, were not registered to vote or held jobs that probably did not pay well enough to finance such donations.

...if a dishwasher gave $1,000 — the campaign sent letters asking them to affirm in writing that the money was their own.

In seven cases, with donations totaling $7,000, questions were raised, and those donors did not respond to requests to confirm their contributions. That money was then returned.