NEW YORK, US - A prominent Democratic fundraiser charged with defrauding Citibank to the tune of 74 million dollars and quickly returning his ill-gotten gains, engaged in yet another fraud to do so, prosecutors said Wednesday.

New York financier Hassan Nemazee was charged August 25 with using fake documents to secure a 74 million dollar loan from Citibank.

At the time, the authorities said that Nemazee, 59, promptly returned the funds.

But in a letter to federal Judge Michael Dolinger in New York, prosecutors say his apparent contrition was faked, alleging that he all he really did was scam a second bank in order to raise the money.

"The line of credit obtained from bank No. 2 was also obtained with the same type of fake documents (fake account statements and forged signatures) that the defendant used to defraud Citibank," US Attorney Preet Bharara said in the letter.

"In other words, Nemazee repaid his fraudulent loan from Citibank with approximately 74 million dollars that he had obtained by defrauding yet another bank."

The bank, and others that prosecutors say Nemazee targeted, were not named in the letter dated September 1 and made public Wednesday.

Nemazee faces a maximum prison term of 30 years and a maximum fine of one million dollars, prosecutors said after his arrest last month.

The scandal is an embarrassment for the Democratic Party, which he supported both as a donor and fundraiser during Hillary Clinton's failed bid for the presidential nomination, and then for Barack Obama's successful White House campaign.