Oil company BP and the makers of Budweiser beer are the latest World Cup sponsors to have voiced their concerns to FIFA over the corruption allegations surrounding Qatar's successful bid to host the 2022 tournament.
Following further allegations by The Sunday Times at the weekend regarding Mohamed bin Hammam lobbying for support for the Gulf state's bid to host the tournament, Sony, Coca-Cola, Adidas, Hyundai and Visa have all come forward to ensure the claims are being fully investigated.
FIFA's longest-standing backer, Adidas, stated that the current atmosphere was "neither good for football nor for FIFA and its partners," while Sony confirmed: "As a FIFA partner, we expect these allegations to be investigated appropriately."
U.S. prosecutor Michael Garcia is due to finish an investigation for FIFA into the awarding of the 2018 and 2022 World Cups to Russia and Qatar respectively, with the findings due in mid-July.
And with the World Cup in Brazil due to start in just three days, the latest sponsors have stepped forward to demand answers.
Anheuser-Busch InBev -- brewers of Budweiser beer, which is signed up as a World Cup tournament sponsor until 2022 -- released a statement saying: "We are concerned about the situation and are monitoring developments; we expect FIFA to take all necessary steps to address the issue."
BP, meanwhile, whose Castrol oil brand is also a sponsor of the upcoming World Cup in Brazil, says FIFA must respond to the allegations in the "right and proper manner."
Qatar's bid committee has said it "upheld the highest standard of ethics and integrity'' during the bidding process for the 2022 tournament.
Bin Hammam was banned from football for life by FIFA in December 2012 over ''conflicts of interest'' while president of the Asian Football Confederation (AFC).
FIFA president Sepp Blatter tweeted on Sunday that that the investigative process into the claims must be given due time.
Never ignoring media reports on ethics allegations in football. But let the Ethics Committee work!- Joseph S Blatter (@SeppBlatter) June 7, 2014