Democratic presidential nominee Barack Obama has claimed he knows nothing about the immigration status of an aunt who has been reported to be living illegally in the US.

A news outlet has suggested that Mr Obama's aunt was ordered to leave the country four years ago by an immigration judge who rejected her request for asylum from her native Kenya.

Zeituni Onyango, 56, who Mr Obama calls Auntie Zeituni in one of his memoirs, has been living quietly in a public housing complex in Boston and is the half-sister of Mr Obama's late father.

Obama campaign spokeswoman Jen Psaki said: "Senator Obama has no knowledge of her status but obviously believes that any and all appropriate laws should be followed."

The campaign questioned the timing of the disclosure just three days before the election.

David Axelrod, Mr Obama's chief media strategist, said: "I think people are suspicious about stories that surface in the last 72 hours of a national campaign. And I think they're ... going to put it in that context."

The story was attributed to two unnamed sources, one a law enforcement official, but said it could not establish whether anyone at a political level in the Bush administration or the McCain campaign had been involved in its release.

It said Ms Onyango's failure to leave the country would be an administrative, non-criminal violation of immigration law. Such cases are handled outside the criminal court system.

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