At the center of the dispute is a 2009 marriage between Omar and British citizen Ahmed Nur Said Elmi, a relationship that has fueled years of speculation, allegations of immigration fraud, and demands for greater transparency from federal authorities.
Recent accounts of an earlier FBI and Department of Homeland Security investigation have brought those questions back into the national spotlight.
Donalds and other Republican critics want to know whether federal officials uncovered evidence of wrongdoing, why prosecutors did not pursue a case, and whether political considerations played any role in the decisions.
