[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2008/images/11/01/art.conyers.gi.jpg caption=" Conyers called for an investigation into the leak over Obama’s aunt."]WASHINGTON (CNN) - A Democratic lawmaker on Saturday asked Homeland Security Secretary Michael Chertoff to investigate a leak to reporters regarding the immigration status of Democratic presidential candidate Barack Obama's aunt, suggesting the Bush administration may have been behind it.
"I was startled to read in today's Associated Press that a 'federal law enforcement official' has leaked information about an immigration case involving a relative of Senator Obama," said a letter sent to Chertoff by Rep. John Conyers, D-Michigan, who chairs the House Judiciary Committee.
"Even more troubling, the AP reports that it 'could not establish whether anyone at a political level in the Bush administration or in the McCain campaign had been involved,' a very disturbing (suggestion) indeed," the letter said.
"This leak is deplorable and I urge you to take immediate action to investigate and discipline those responsible."
The AP reported Saturday that Obama's Kenyan aunt, Zeituni Onyango, is living in the United States illegally, even though an immigration judge rejected her request for asylum four years ago. The story cites two sources, one of them a federal law enforcement official.
CNN has not been able to independently verify the aunt's immigration status. Immigration and Customs Enforcement spokeswoman Kelly Nantel declined comment, saying the agency "is prohibited from commenting on any individual's status."