CHICAGO — Democratic presidential nominee Barack Obama said yesterday he didn't know his aunt was living in the United States illegally and believes that laws covering the situation should be followed.

The Associated Press found that Obama's aunt had been instructed to leave the country four years ago by an immigration judge who rejected her request for asylum from her native Kenya. The woman, Zeituni Onyango, is living in public housing in Boston and is the half-sister of Obama's late father.

A statement given to the AP by Obama's campaign said, "Senator Obama has no knowledge of her status but obviously believes that any and all appropriate laws be followed." Traveling with Obama in Nevada, campaign strategist David Axelrod would not elaborate on the statement, but said: "I think people are suspicious about stories that surface in the last 72 hours of a national campaign."

The campaign said it was returning $260 that Onyango had contributed in small increments to Obama's presidential bid over several months. Federal election law prohibits foreigners from making political donations. Onyango, 56, listed her employer as the Boston Housing Authority and last gave $5 on Sept. 19.

Obama's father, Barack Obama Sr., left the future presidential nominee when the boy was 2, and they reunited only once — for a monthlong visit when Obama was 10. The elder Obama lived most of his life in Kenya. He died in a car crash in 1982.

Obama was raised for the most part by his mother and her parents in Hawai'i. He first met his father's side of the family when he traveled to Africa 20 years ago. He referred to Onyango as "Auntie Zeituni" when describing the trip in his memoir, saying she was "a proud woman."