McCullum stands by his testimony

New Zealand captain Brendon McCullum has denied he has ever been involved in matchfixing and stood by his evidence to an International Cricket Council investigation into corruption.

McCullum added he was "disappointed" that excerpts of his testimony had been leaked to the media after it was reported he had told investigators that a former player approached him about corrupting matches in 2008.

"Let me be clear I have never ever fixed a cricket match," he said in a statement before appearing at a media conference in Christchurch on Thursday.

"I am 100 percent behind the fight against corruption in the sport."

McCullum arrived back in New Zealand from India on Thursday to attend the birth of his third child and faced reporters in Christchurch to address the growing scandal, which came to light last December with reports that three former New Zealand players were being probed for alleged match-fixing.

"Yep," McCullum answered when asked if he stood by his testimony to the the ICC's Anti-Corruption Security Unit (ACSU).

"I gave my testimony to the ICC in good faith so I was shocked when I read it in the media.

"I hope it does not stop others coming forward in the future as all players need to play their part in stamping out corruption."

A British newspaper quoted McCullum as telling investigators that he had been approached twice in 2008 about matchfixing by a former international player identified as 'Player X'.

Former New Zealand all-rounder Chris Cairns, who has consistently denied being involved in any matchfixing, said his name had been "linked by others" to corruption allegations.

"I am being asked whether I am Player X," he said in a statement to Fairfax Media.

"Based on the limited information I have received during this investigation, I believe it is being alleged that I am that player. These allegations against me are a complete lie."

McCullum had "no comment" when asked whether Cairns was 'Player X'.

LEAK

"With regards to my testimony and the fact it has been aired in public I'm obviously very disappointed about that," McCullum said.

"I can't go into ... what's going into the investigation or my involvement in it ... but I will continue to fulfil my role in the investigation.

"I guess from my point of view the dealings I've had with the group that I've dealt with, I have confidence.

"How the leak happened, I'm not sure but I have confidence in them.

"If one of the players found themselves in the same situation, I would encourage them to go down the same path."

ICC president Alan Isaac said the organisation had begun an investigation into the leaks and had sought an injunction against the British newspaper that had published them.

"It is terrible this has leaked," he told Radio New Zealand. "(ICC chief) Dave Richardson has made some enquiries and we don't believe it has leaked from any of our people.

"We have taken steps to try to injunct the media to try and stop them releasing any further information they have," he said.

"We are really just trying to stop them on grounds that it's not helpful."