Brendon McCullum stands by the evidence he gave against Chris Cairns last year and the former New Zealand captain hit out at the International Cricket Council's (ICC) anti-corruption unit for showing a lack of professionalism.

McCullum alleged at former Black Caps team-mate Cairns' perjury trial that his former Black Caps team-mate twice approached him about manipulating matches in India eight years ago.

Cairns was found not guilty of perjury and perverting the course of justice by a jury at Southwark Crown Court after a nine-week trial.

Speaking at the MCC Cowdrey Spirit of Cricket lecture at Lord's, McCullum said he stood by what he said as a key witness and slammed the ICC's casual approach when he initially reported his allegations.

"I think it is appropriate, standing here at 'the Home of Cricket’ to confirm that I stand by everything said in my statements and the evidence I gave at Southwark Crown Court," said McCullum.

Recalling his first interview with a member of the ICC anti-corruption unit, the 34-year-old stated: "[He] took notes - he did not record our conversation.

"He said he would get what I said down on paper and that it would probably end up at the bottom of the file with nothing eventuating.

"Looking back on this, I am very surprised by what I perceive to be a very casual approach to gathering evidence. I was reporting two approaches by a former international star of the game.

"I was not asked to elaborate on anything I said and I signed a statement that was essentially nothing more than a skeleton outline.

"I think players deserve better from the ICC and that, in the future, the evidence gathering exercise has to be much more thorough, more professional.

"In my opinion a person taking a statement should ensure that the witness is advised about what may occur."

McCullum also slammed the ICC after the evidence he gave in court was leaked to the media.

"How can the game's governing body expect players to co-operate with it when it is then responsible for leaking confidential statements to the media?" he questioned.