Brendon McCullum, the former New Zealand captain, has criticised the International Cricket Council for a lack of professionalism and confidentiality when handling his match-fixing evidence and warned players may be deterred from coming forward in future.

McCullum, 34, who retired from international duty in February, was the speaker at the MCC’s annual Spirit of Cricket Cowdrey lecture at Lord’s on Monday night and used the opportunity to outline his experience as a key witness in the Chris Cairns perjury trial in November last year.

Cairns, the former New Zealand all-rounder, was found not guilty of perjury and perverting the course of justice, having been accused of falsely stating he had never cheated at cricket during a successful libel action against Lalit Modi, the former Indian Premier League chairman, three years earlier.

McCullum was one of two former team‑mates, along with the self-confessed match-fixer Lou Vincent, to testify during the eight-week trial at Southwark Crown Court, accusing Cairns of twice approaching him to rig games in 2008 and telling him “everyone else was doing it in world cricket”.

Cairns’s defence team made much of the fact McCullum reported these approaches three years later and highlighted changes to his account of events in two statements given to the ICC’s anti-corruption and security unit in 2011 and 2013, as well as one to the Metropolitan police in 2014.

Speaking at Lord’s on Monday, McCullum said he stood by his evidence but criticised what he described as “a very casual approach to gathering evidence” by the ICC investigator John Rhodes when taking down his initial statement, as highlighted by both the need for a second account of events two years later and a subsequently more thorough approach by the Met police.

He said: “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.”

McCullum went on to outline his frustration at seeing the statements he had given to the ICC’s anti-corruption unit appear in the Daily Mail in 2014, claiming it caused him personal distress and harms the chances of players giving evidence in future.

He said: “To report an approach and to give evidence requires considerable courage – players deserve much better. 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?

“It goes without saying that, if players do not have confidence in the organisation, they will be reluctant to report approaches and the game is worse off. If we are to get rid of the scourge of match-fixing, a robust governing body is essential.”

The ICC released a statement when the story appeared in the Daily Mail saying it had not shared the information and promising an investigation into how McCullum’s testimony had become public.

On his decision to testify against Cairns, McCullum said: “I believe I had a moral obligation to tell the truth – and I believe that the interests of the game of cricket and common decency demanded my attendance [at court]. But I do wish that the ICC had handled my initial approach more professionally for the reasons I have given.”

McCullum also criticised the 11 life bans given to Vincent by the England and Wales Cricket Board two years ago, claiming the former Lancashire and Sussex batsman’s mental health problems at the time of his corrupt activities from 2008 to 2012, as well as his full confession to fixing that followed, deserved a greater degree of clemency.

McCullum said: “If players cooperate with the authorities and provide the game with a rare and critical insight into the workings of this pernicious influence, then there must surely be something that can be done beyond giving them the maximum ban available.

“I have no doubt that the ECB’s severe punishment of Lou has robbed the game of a golden opportunity to have him provide education to players, something I feel could have made a difference in the future. Further, it ignored his extreme vulnerability in a callous way.”