Obama's aunt the focus of visa scandal

The scandal over Barack Obama's "Auntie Zeituni" sparked a Department of Homeland Security investigation yesterday, after it emerged that the Democratic candidate's close relative was living illegally in the United States.

Officials are investigating whether its privacy policy was breached when details regarding the immigration status of Zeituni Onyango, one of many half-sisters of Obama's father, Barack Snr, were leaked to a news organisation.

The Associated Press reported late on Friday that the woman, who lives in council housing in Boston and has made several donations to Obama's campaign, had been instructed to leave America four years ago by a judge who rejected her request for asylum from her native Kenya. News of the affair prompted the US Immigration and Customs Enforcement agency to refer the affair to Homeland Security, in an attempt to establish how confidential details regarding Ms Onyango's case were made public.

"They are looking into whether there was a violation of policy in publicly disclosing individual case information," said a spokesman.

When Ms Onyango's case hit the headlines at the weekend, several senior Democrats claimed it marked a "dirty tricks" campaign to discredit their candidate in the closing stages of the campaign. "Senator Obama has no knowledge of her status but obviously believes any and all appropriate laws be followed," said campaign strategist David Axelrod. "I think people are suspicious about stories that surface in the final 72 hours of a national campaign."

The woman last spoke to the Democratic candidate two years ago, said campaign sources, and was also present at Mr Obama's swearing-in to the US Senate in 2004. But the Illinois senator had no role in helping her gain the tourist visa for that trip – which she subsequently overstayed – and claims to be unaware of any subsequent details of her stay. In an attempt to kill coverage of the affair, the Obama campaign yesterday agreed to return $260 (£160) that Ms Onyango had contributed in small increments over in recent months. According to records, she had last given $5 on 19 September.

Although the Associated Press claimed ignorance of whether anyone in the Bush administration or McCain campaign had been involved in the release of details about Ms Onyango, senior Democrats were unconvinced.

The House Judiciary Committee Chairman John Conyers wrote to the Secretary of Homeland Security, Michael Chertoff, requesting an immediate investigation. He said it was "was not the first leak of law enforcement information apparently designed to influence the coming presidential election," apparently referring to an ongoing investigation of voter fraud by the Association of Community Organisations for Reform Now, or Acorn.

Meanwhile, John McCain's campaign seemed reluctant to capitalise on the story. Official spokesmen declined to comment, while former New York mayor Rudy Giuliani, told reporters: "I don't think families should be hounded."

The Onyango case: A mysterious leak

Mr Obama's half aunt on his father's side, Zeituni Onyango, 56, was ordered to leave the US four years ago when she was denied political asylum. The story broke after The Times tracked her to Boston last week. The Associated Press then reported the news about her deportation case, raising suspicions it was leaked by the Bush administration. Immigration and Customs Enforcement says it cannot comment on an individual's immigration status.