The FIFA president, who is being challenged by Bin Hammam in a presidential election on June 1 in Zurich, announced the initiative on Monday aimed at combatting illegal betting and match-fixing which threaten the integrity of the game globally.
However, in a message on his personal website on Thursday, the 62-year-old Qatari said the FIFA executive were never consulted about the donation to Interpol, the largest single grant the organisation had received from a private institution.
Bin Hammam also said that while FIFA's name had "been dragged through the mud once more" by allegations made by David Triesman in London this week, he did not believe the organisation was corrupt.
He continued: "Currently, the President has taken on too much of an Executive role, as evidenced by the recently announced initiative to donate 20 million dollars to Interpol. Imagine FIFA financing Interpol's activities!
"This decision was taken arbitrarily by the FIFA President and was not discussed with the Executive Committee.
"It is just another example of the current regime choosing to run football how it sees fit, rather than doing so in a manner that is consistent with the governing body's proper procedures. How on earth can we convince people of FIFA's innocence?"
SOMETHING URGENT
FIFA later refuted suggestions that Blatter had approved the donation to Interpol alone.
"The chairman of the FIFA Finance Committee was consulted with regards to this payment made by FIFA before the agreement was signed," the statement said.
It also said the donation was not a one-off payment but spread evenly over 10 years.
While stating that FIFA's image had been damaged, Bin Hammam, the president of the Asian Football Confederation, said he did not believe the organisation was corrupt.
"It has become clear yet again in recent days that something urgently needs to be done to improve and enhance the image of FIFA; the name of our great sport and its leading institution have been dragged through the mud once more," he said.
"I will happily and unreservedly restate that I firmly believe FIFA, as a decision-making body and as an organisation, is not corrupt.
"Football is a force for good and FIFA is at the vanguard of making positive changes across the world.
"However, under the current status quo it is impossible to deny that the governing body's reputation has been sullied beyond compare and it is time for that to change.
"A new atmosphere needs to descend upon FIFA; there needs to be an opportunity for new ideas to take hold and for the organisation to take a new direction."
FIFA's ethics have been in the spotlight this week after Triesman, the former chairman of the English FA, accused four executive committee members of seeking bribes in return for their vote for England's bid for the 2018 World Cup finals.
Two other members were accused of taking bribes to vote for
