WASHINGTON — The Department of Homeland Security is investigating whether its privacy policy was violated after a news organization reported that an aunt of Democratic presidential nominee Sen. Barack Obama is an illegal immigrant from Kenya, officials said this weekend.

The woman, Zeituni Onyango, 56, lives in a public housing complex in Boston and is the half sister of Obama's late father, who spent most of his life in Kenya before dying in a car accident in 1982.

The Associated Press reported late Friday that Onyango was denied asylum by an immigration judge and that she was instructed to leave the United States in 2004. The AP cited two unnamed sources, identifying one as a federal law enforcement official.

Federal privacy law restricts U.S. immigration agencies from disclosing information about citizens and permanent residents, and DHS policy similarly limits disclosures about the status of legal and illegal immigrants. Asylum-seekers are granted greater protection, because of the sensitive nature of their claims and the risks of retaliation.

In a statement, a spokeswoman for U.S. Immigration and Customs Enforcement said the matter has been referred to the agency's Office of Professional Responsibility and its parent department's inspector general.

"They are looking into whether there was a violation of policy in publicly disclosing individual case information," ICE spokeswoman Kelly Nantel said. "We can't comment on individual cases."

After Obama's campaign announced Saturday morning that it will refund a small number of contributions made by Onyango, two government officials confirmed that Onyango had sought asylum, citing violence in her native Kenya. One federal law enforcement official confirmed that a federal administrative judge ruled in 2004 she was not legally entitled to be in the United States and that a final order was entered for her deportation.

While such denials can be appealed, cases are generally decided within a year or two, according to federal statistics. Of about 12 million illegal immigrants estimated to be in the United States, about 550,000 are "fugitive aliens" staying in violation of deportation orders.

Reports filed with the Federal Election Commission show Onyango gave Obama's campaign a total of $265, including several contributions of $5 and $25. The latest recorded contribution, of $5, was on Sept. 19. Only U.S. citizens and legal permanent residents, known as green cardholders, can legally contribute to federal presidential campaigns.

"Given the information that has been brought to our attention, the contributions are being refunded," said Ben LaBolt, an Obama campaign spokesman. "Senator Obama has no knowledge of her status but obviously believes that any and all appropriate laws be followed."

Mark Salter, a McCain adviser, called the issue "a family matter."

In his 1995 memoir, "Dreams From My Father," Obama described meeting the woman he calls Auntie Zeituni and other members of his large paternal family after he first traveled to Kenya in 1988 upon learning of his father's death. Obama wrote that Onyango was a tall, spirited woman who called herself "the champion dancer" and worked as a computer programmer in Nairobi.

Obama was raised mostly by his mother and her family in Hawaii after his father returned to Kenya when Obama was 2. Obama was reunited with his father once, for a month, at age 10.

Obama and his future wife, Michelle, met Onyango on a subsequent visit to Kenya in 1992, and she visited the Obama family in Chicago on a tourist visa about nine years ago, his campaign said. Onyango attended Obama's U.S. Senate swearing-in ceremony in 2005, and the senator last heard from her about two years ago, according to the campaign.

A campaign source said Obama provided Onyango no assistance in obtaining a tourist visa or housing, or in her immigration case.

In an interview with the Times of London, which first reported Onyango's presence in Boston and her campaign contributions, Onyango said she had traveled to and from the United States since 1975. Commercial databases indicate she received a Social Security card in 2001, indicating she was legally present and authorized to work at that time.

Onyango was not at her state-subsidized West Broadway residence Saturday in South Boston, and no one answered her telephone.

William McGonigle, deputy director of the Boston Housing Authority, said Onyango applied for public housing in 2002 and was approved in 2003 as an eligible noncitizen. She was paid a small stipend for volunteering as a resident health advocate starting in December 2007, he said.

McGonigle said that housing officials were not notified of her deportation order and that they followed all federal rules and laws in providing her stipend. He said housing officials were not aware that Onyango was related to Obama until the Times of London phoned last week.

Rakowsky reported from Boston. Staff writers Keith B. Richburg in New York and Matthew Mosk, and staff researcher Julie Tate, contributed to this report.