The NSW Crime Commission (NCC) has ordered staff to review allegations that its landmark report into money laundering through poker machines may have been "compromised".
An investigation by the powerful body last year found billions in "dirty cash" was being funnelled through electronic gaming machines in pubs and clubs across the state.
Project Islington found that most of these instances included criminals gambling with ill-gotten gains, but that using pokies to launder — or "clean" — cash was not as widespread.
The report formed the basis for debate on gambling reform in NSW, with the Minns government pledging to trial cashless gaming at some venues.
Independent MP Alex Greenwich has now raised concerns about the accuracy of the data on money laundering, saying he had been told "the full extent" may not be reflected in the report.
On Thursday, Mr Greenwich told state parliament he was informed that the investigation may have been "constrained", due to it not having all data collected by Liquor and Gaming NSW.
The house passed a motion he introduced calling for a range of documents to be produced to parliament.
“It covers information that has been brought to my attention that may have constrained the investigations by the crime commission," he said.
Mr Greenwich told ABC Radio on Friday that "two very reliable sources" had brought these concerns to his attention.
Among the allegations were that some pubs and clubs had been "tipped off" about upcoming compliance checks.
"[The sources] have indicated to me that the type and extent of money laundering that was occurring in pubs and clubs in New South Wales, the full extent of that was not accurately reflected in the report," he said.
“That there is further information, data and advice within Liquor and Gaming.
“And that there are also associated correspondence with that which has been suggested to me that pubs and clubs may have been tipped off about compliance checks in advance.”
Mr Greenwich did not accuse Liquor and Gaming or any government ministers of wrongdoing, and said it remained "unclear" whether information was deliberately withheld.
NCC Commissioner Michael Barnes released a statement on Friday saying staff had been directed to review the allegations.
"For obvious reasons, it is essential that the commission can be confident that the evidence base underpinning its reports are sound and comprehensive," he said.
"We will take whatever steps that are necessary to ensure the integrity of our investigation in this matter has not been compromised.
"At the same time, we are respectful of processes underway in parliament, and we need to ensure that we do not cut across those. I have today discussed the matter with Mr Greenwich to be sure that doesn’t happen."
A Liquor and Gaming NSW spokesperson said the body was an active participant in Project Islington and worked closely with the NCC for 10 months.
They said all "relevant information" collected by its analysis and evidence gathering was provided to the inquiry or to other agencies such as AUSTRAC.
"L&GNSW is not aware of any cases of venues being given prior warning of our investigative work related to Project Islington," the statement said.
"L&GNSW will comply with all parliamentary orders relating to this matter."
Mr Greenwich has been an advocate for gambling reform and supports the introduction of mandatory cashless gaming in NSW.
