McComb, who lost on points to England's Luke McCormack in the round of 16 in the 64kg category on Sunday, was fined A$756 (£413.2) after the incident outside Sin City nightclub early on Tuesday.
Local media reported that the 25-year-old had been ejected from the venue and then fought with bouncers outside after trying to re-enter.
Northern Ireland's chef de mission Robert McVeigh apologised to the "people of the Gold Coast" on Tuesday and said the delegation would launch its own investigation.
On Thursday, however, the NICGC said its reputation had been "impugned" after talking with the boxer and reviewing CCTV footage of the incident.
"The NICGC has reviewed the latest evidence and determined that team sanctions will not be taken against Sean in relation to this incident and we can confirm that he remains an integral member of the boxing squad and the wider team," it said in a statement published by the BBC.
"In our opinion he is an innocent victim in this matter and he retains the full support of the NICGC.
"We are disappointed that the reputation of the athlete and the NICGC is being impugned, and we want to ensure that every opportunity is available to resolve this matter.
"To this end, legal advice is being sought and the Foreign and Commonwealth Office is being kept informed."
The NICGC added that it had asked Queensland state police to fast track a review of their decisions, which included banning the boxer from attending nightclubs in the Gold Coast's party districts.
(Editing by Peter Rutherford)
