"WASHINGTON (Reuters) - One of U.S. President Barack Obama's closest aides was paid $100,000 by a company doing business with Iran just before joining the White House staff, the Washington Post reported on Monday, raising awkward election-year questions for the Democrat trying to get tough with Tehran.

White House senior adviser David Plouffe received the speaking fee from Africa's biggest wireless phone operator, MTN Group, for two speeches he made in Nigeria in December 2010, the company and administration officials confirmed.

Plouffe listed it with many others on his official financial disclosures after he joined the White House in January 2011. An MTN subsidiary is a major shareholder in Irancell, a major government-connected telecommunications operator in Iran."