The investigator has been on extended sick leave since the incident. He is also the company’s internal auditor.
In March, he emailed the chairman, Phil Meaney, to say details had been withheld from his team and notes had not been shared.
He told Mr Meaney that this, along with other issues around the closing-out of its report into the scam, had led him to believe the work was being thwarted.
“The withholding of the notes from the investigating team was an attempt to obstruct our investigation, [under] Section 44 (4) of Greyhound Industry Act, 1958, and the production of these notes now at such a late stage is a further attempt to discredit our investigation,” he said.
In response, Mr Meaney said he objected to the internal auditor raising concerns in this way and said he had not sought to influence the investigation.
“I utterly reject and refute your allegations that I either have or am currently working to obstruct our discredit your investigation or subvert The Greyhound Industry Act 1958,” said Mr Meaney.
He said he would leave it up to the internal auditor to decide if he should apologise for the allegations made in the original email.
In a follow-up statement, the IGB said the suggestion was defamatory.
The investigation team’s report had uncovered a meticulous race fixing scam had taken place at Dundalk Stadium. However, this had not been spotted by the original regulation inquiry conducted by the IGB.
The auditor’s allegations against the chairman was the second time concerns about Mr Meaney’s interaction with the integrity inquiries had been aired.
In 2011, an independent investigator, Frank Melville, had been appointed from England to review the incident.
However the then IGB director, Danny Reilly, called on the chairman to consider his position because certain documents had not been passed to the investigator.
Mr Reilly said Mr Melville had not got full co-operation from the IGB.
Mr Reilly said the investigator had felt obstructed when he sought to inquire into the Dundalk rigging case and a separate doping matter in Cork.
Mr Melville eventually produced a brief, two-page, summary report which recommended the fresh investigation into the Dundalk affair.
The resulting internal report was finalised earlier this year by the company’s internal auditor and its head of compliance. It documented the incident and how it escaped detection.
Both men have been out on sick leave since it was presented to the board.
In a letter to junior agriculture minister Tom Hayes a director of the IGB, Brendan Moore, asked him to investigate the circumstances.
Despite a statement early this year that the report into the fixing scam would be published, the IGB has since decided to set the work of its two internal investigators aside and it has looked to produce a separate summary review.
Details of the Dundalk report was published by the Irish Examiner in February, at which time the IGB said it had been adopted by the board and its recommendations had been implemented.
However, in a follow-up email, the internal auditor told Mr Meaney that the report’s recommendations could not have been adopted as it had not be passed to the regulation team.