WASHINGTON — Responding to a report that a Kenyan relative of Sen. Barack Obama was living in the United States illegally, his campaign on Saturday said that he had no knowledge of her immigration status and that "any and all appropriate laws" should be followed.

The woman, Zeituni Onyango, referred to as "Auntie Zeituni" in a passage in Obama's memoir, applied for political asylum in the United States in 2004, but a federal immigration judge rejected her request and instructed her to leave the country, said a government official with knowledge of the case who asked not to be identified because of its sensitive nature. Onyango's legal status was first reported by The Associated Press on Friday.

Onyango is the half-sister of Obama's father and is part of an extensive network of paternal relatives with whom Obama has had limited contact, his aides said. Obama, who was largely raised by his maternal grandparents in a modest apartment in Honolulu, first met Onyango when he traveled to Africa as an adult.

Onyango attended the ceremony when Obama was sworn in to the U.S. Senate in 2004, but campaign officials said he had provided no assistance in getting her a tourist visa and did not know the details of her stay. At the time of the ceremony, Onyango and another relative said in interviews that they had flown to the United States from Kenya to witness the moment.