The publicity could also affect how Onyango is treated, both here and back in her homeland, lawyers say.

"She's the aunt of the president of the United States -- the most famous man in the world," Mike Rogers, spokesman for the Ohio law firm defending Onyango, told the Boston Herald.

The newspaper reported that Onyango has requested the case be heard before a closed session, though that is not unusual in immigration hearings.

"The immigration judge will hear the merits of the case from both parties," said Lauren Alder Reid of the US Department of Justice's Executive Office for Immigration Review, which speaks for the court. "The judge may make a ruling from the bench, but there's no guarantee."

Onyango has said she never asked Obama for help and that she cut off any ties to the president. It remains unclear who is paying for her legal representation, since Onyango has been living in public housing and has no known funds of her own.

She is the half-sister of Obama's late father, who was Kenyan and married a white American, who gave birth to Obama in Hawaii.

Onyango moved to the United States in 2000 and applied for political asylum two years later, but was turned down. She was ordered deported in 2004.