Minister for Justice Simon Harris has said a full investigation needs to be carried out following the resignation of an experienced investigator at GSOC.
Mr Hutch was found not guilty of the murder of David Byrne that day and walked free from the Special Criminal Court.
The claim came to the attention of other members of staff in GSOC and was reported to senior management.
The investigator, who has worked with GSOC for the past number of years, was due to be suspended and would have to surrender his phone and identity card. He took the decision to resign instead.
Speaking yesterday, Mr Harris said this was a "very serious matter" and needed to be treated as such.
He said he had sought a report from the chair of GSOC, which he expected to receive in the coming days.
"It is absolutely clear an investigation will be required here," he said, adding that the form it would take will become clear once he receives the chairperson's report.
Mr Harris said: "Maintaining public confidence in GSOC who carry out such a vital job is absolutely essential."
He said it was a statement of fact that if there is any allegation of criminal wrongdoing, it would require gardaí to be involved.
But Mr Harris added: "I think it's important that the facts are ascertained. This is a very serious matter which deserves and requires a full investigation."
Asked about a call from the Association of Garda Sergeants and Inspectors for an external investigation to be carried out into GSOC after the association said an investigation by GSOC into itself was "unsatisfactory," Mr Harris said it was important that the confidence of everybody be maintained in GSOC.
He said GSOC did a vital job in its ombudsman and oversight role.
The GSOC officer, who has been involved in several major investigations into potential garda misconduct, told a number of people that he had been at a house party that Mr Hutch attended.
It is not clear whether the GSOC investigator actually attended a party or just said he had attended a party that was also attended by Mr Hutch.
However, the issue has raised major concerns in GSOC because of the potential for compromise or a security breach at the organisation, and is being taken very seriously.
GSOC revelations not being understated by Govt, says O'Brien
Yesterday, Minister for Housing Darragh O'Brien said the seriousness of the GSOC revelations is not being understated by anyone in the Government.
However, he said it was a single matter which has been dealt with and he does not believe it will have a further "contagion effect".
"I don't think we can read into that, that it goes any further," he said.
Mr O'Brien added that the investigation into the matter must now be allowed to commence and conclude.
Minister of State at the Department of Finance Seán Fleming described the news as shocking, saying that everybody was taken by surprise, and that GSOC have to get the full facts.
He said that depending on what emerges, it may need to be referred for a full inquiry to An Garda Síochána.
The GSOC officer in question was involved in a number of highly sensitive investigations into An Garda Síochána, including the investigation into the death of Superintendent Colm Fox, who took his own life in Ballymun Garda Station in 2019.
Supt Fox was the lead detective in the investigation into the murder of David Byrne at the Regency Hotel during the time Patrick Hutch Junior was charged and appeared in court.
The case against Patrick Hutch Junior collapsed following the death of Supt Fox.
