"To be clear, I have never approached Brendon or anyone else about match fixing or any other improper activity," Cairns said. "I am doing everything I can to get to the bottom of these allegations."
Cairns said he had not yet been interviewed by ICC investigators. However, he has been interviewed by officers of the London Metropolitan Police who traveled to New Zealand as part of a separate investigation.
He said he was not aware of the nature of that inquiry. Cairns' London-based lawyer, Andrew Fitch-Holland, was arrested in March by officers from the Met on suspicion of perverting the course of justice.
"I ask that people reserve judgment until all the facts are brought to light," Cairns said. "I have nothing to hide.
"I have been to court to demonstrate conclusively that I am not a match-fixer before. I will have no hesitation in doing so again."
Cairns said there were "dark forces at play" in the latest round of fixing allegations.
"These forces have long arms, deep pockets and great influence," he said. "I acknowledge that recently I have upset some powerful people in the world of cricket, including raising my own concerns about the health of the game.
"I believe I am paying the price for that now."
New Zealand Cricket acted quickly on Monday to demonstrate its support for McCullum after details of his testimony were published. In a statement, NZC said it was dismayed that McCullum's evidence had been leaked to the media and stressed that the national team captain was not guilty of any wrongdoing.
"He is not under investigation and his testimony has been applauded by the ICC," chief executive David White said. "He was approached and he rebuffed those approaches and he reported it to the ICC. We believe he's done the right thing and we've got 100 percent confidence in our captain and in his role in tackling corruption."
