The Irish sports minister has called for an independent investigation into claims Olympics tickets allocated to an Irish seller were on sale illegally.
Two people were arrested in Rio last week after official Irish tickets were allegedly found on sale in Brazil.
The Olympic Games organisers have sent written questions to Pro 10 Management, a Dublin firm chosen as the Authorised Ticket Re-seller (ATR) in Ireland.
The Olympic Council of Ireland has also begun its own internal inquiry.
In a statement on its website on Thursday, the Olympic Council of Ireland said it "strictly adheres to the International Olympic Committee regulations around ticket allocation, sale and re-sale".
"We are treating this matter with the utmost seriousness," it added.
However, Irish Minister for Sport Shane Ross said he was uneasy about the Olympic Council of Ireland's internal inquiry and said it was essential that the issue is independently investigated.
He told Irish broadcaster RTÉ that his government was not ruling out investigating the issue itself, but had to take into consideration that three separate investigations had already begun, including a criminal inquiry.
"What we've got to do," Mr Ross said, "is to make an assessment now of whether these inquiries are adequate to satisfy the dissatisfaction of the Irish people."
The minister is due to meet Olympic Council of Ireland president Pat Hickey in Rio on Sunday to discuss the issue.
The two people who were arrested in Brazil are reported to be an Irish businessman and woman working as an interpreter.
They were questioned about the fraudulent marketing of tickets.
The Director of Ticketing for Rio 2016 Donovan Ferreti told RTÉ that the Olympic authorities are seeking information from the Irish ATR Pro 10 Management.
"We sent some questions, and as soon as we receive the information we will try to figure out what happened with these tickets," Mr Ferreti said.
The Olympic Council of Ireland's president said his organisation had nothing "whatsoever" to do with handling the sales of Rio 2016 tickets but has been in contact with its own officially appointed ticket agent, Pro 10 Management.
"We've sent them a list of questions and we want detailed answers to each question so we can assemble all the facts," Mr Hickey told RTÉ.
He added that they had also "written to the Brazilian authorities in Rio 2016 and we have asked them can they send us all the necessary documentation and any evidence whatsoever that they have".
In a statement on Thursday, Pro 10 Sports Management said it had been "made aware of the ticketing situation in Rio".
"Pro 10 Sports Management have at all times strictly complied with all regulations around ticket sales and re-sale."
The BBC has also contacted Pro 10 Management to request an interview but the firm has not yet responded.