FIFA's hospitality partner MATCH insists it has compete faith that director Ray Whelan has not broken any laws.
The comments came after the Englishman was arrested in Brazil as part of an investigation into illegal ticket sales at the World Cup.
Whelan was arrested in Rio de Janeiro on Monday as part of Operation Jules Rimet, Brazilian police's investigation into ticket touting.
It has seen detectives tap phones, make a total of 12 arrests and seize a number of tickets.
MATCH said in a statement it believes Whelan, who has been released by the police but will continue to help with further investigations, will be proven to be innocent of any wrongdoing.
It said: "Ray Whelan has been released from police custody and will assist the police with further enquiries.
"MATCH have complete faith that the facts will establish that he has not violated any laws.
"MATCH will continue to fully support all police investigations, which we firmly believe will fully exonerate Ray.
"In the meantime, Ray Whelan, as well as the rest of the MATCH personnel, will continue to work on our operational areas of responsibility in order to deliver a successful 2014 FIFA World Cup Brazil."
Whelan, who used to work as an agent for Bobby Charlton, was arrested at the Copacabana Palace in Rio de Janeiro, the hotel reserved for FIFA's senior executives.