Argentina's Clarin newspaper reported in 2005 that the man's grandfather had migrated with Menem's father from the same town in Syria.
The extent of the families' later contact was not immediately clear.
Menem rejected the accusations then, saying the allegation was "a libellous and nasty fable" and blamed it on Cristina Fernandez, the president, and her husband, Nestor Kirchner, a former president, who Menem said used the case "systematically and vilely" for political ends.
A truck bomb destroyed the seven-storey Argentine Israeli Mutual Association building, a centre for Latin America's largest Jewish community, in the attack.
Argentina has accused Iranian officials of plotting the attack and Interpol issued international wanted notices at Argentina's request for five Iranians, including senior officials.
Menem also faces charges in a separate case involving his role in a scheme to smuggle weapons to Croatia and Ecuador while both countries were involved in wars in the 1990s.