Two previously unknown emails suggest Mr Annan may have known that a company employing his son’s employer was vying for a multi-million dollar UN contract, despite his repeated denials.
An independent commission and several US congressional committees are reviewing Kojo Annan’s involvement in securing the bid and his father’s role in the process.
The final version of the independent inquiry’s report is due out in the next few months.
The UN has refuted a memo issued by Swiss consulting firm Cotecna describing a meeting between Mr Annan and its executives in 1998, weeks before it was awarded the contract.
“He had no knowledge that Cotecna was a contender for that contract,” said UN spokesman Fred Eckhard at a press briefing at UN headquarters in New York.
Cotecna, which once employed Mr Annan’s son Kojo, was awarded a $US10 million ($A13.15 million) a year contract in 1998 to inspect goods entering Iraq as part of the oil-for-food program.
A previous inquiry reports cleared Mr Annan of involvement in the scandal, however criticised him for failing to investigate whether there may be a conflict of interest.
The inquiry committee now said it will “conduct additional investigation regarding this new information”.
On Tuesday, The New York Times newspaper said it had obtained a copy of a memo written on December 4, 1998, by then Cotecna vice president Michael Wilson, described by the paper as a family friend to the Annans.
The memo described a meeting in late November 1998 during the 20th summit of Francophone leaders in Paris.
“We had brief discussions with the SG and his entourage,” the memo states, written on December 4, 1998 and addressed to Cotecna’s top three officers.
“We could count on their support,” the memo continues.
A second email expressed the executive’s confidence that the company would win the contract because of “effective but quiet lobbying” in New York diplomatic circles, according to an Associated Press report.
Mr Eckhard said the United Nations had looked at trip records for Mr Annan’s November 1998 Paris visit “and there is no mention in that trip record of any exchange with Michael Wilson,” he said.
The email was apparently found three weeks ago during a search of the Geneva-based company’s archives.