The Qatari questions Blatter's role and spending policy in tackling corruption in the game.
Bin Hamman turns up the heat on Blatter
The battle for the Fifa presidential hot seat has intensified after Mohamed bin Hammam criticised Sepp Blatter for spending the governing body's money "arbitrarily" on an Interpol program without consulting the executive body.
Bin Hammam is challenging Blatter in Fifa's presidential election on June 1 and the Qatari said on Twitter that Blatter "has taken on too much of an executive role" by announcing plans to donate ?20 million ($29 million) to Interpol to tackle match-fixing and betting fraud over the next decade.
Bin Hammam, 61, said: "Imagine Fifa financing Interpol's activities!"
He said the decision "was taken arbitrarily by the Fifa President and was not discussed with the Executive Committee."
Blatter, who is under pressure to address alleged corruption with the 2018 and 2022 World Cup bidding, has made fighting corruption a central campaign theme.
He has. however, won the backing of Oceania's 11 soccer nations in his re-election campaign. Oceania Football Confederation President David Chung says all the members agreed that Fifa under Blatter has had a "significant impact" on soccer's development and popularity in their region.
Chung said the 11 nations can still independently choose to back bin Hammam, but today's decision shows "unity and transparency" in Oceania. Blatter, who's been president since 1998, also has been publicly supported by leaders of European authority Uefa and South America's CONMEBOL confederation. Fifa's 208 national members will vote June 1 at their congress in Zurich.