There were reports that Australia's slow batting in the match against Zimbabwe was investigated by the ICC's anti-corruption unit. Clark said the ICC only fuelled the speculation by giving just a "no comments" response.
"Maybe this is the conspiracy theorist coming out in me, but, having toured that part of the world, I understand how much winning the World Cup means not only to the Indian team but to the nation," he said.
"It was pleasing to see Australia's team manager, Steve Bernard, come out and rubbish these claims but disappointing to hear the ICC provide an inadequate response by offering only a 'no comment'.
"Is it asking for too much for the ICC to offer a meaningful comment? Is it too much to ask that the game be presided over by a governing body that is capable of acting professionally?" he added.