Just 12 percent of tickets have been sold for the 2016 Paralympic Games, which start in three weeks.
The poor sales figures were confirmed by Rio 2016 spokesperson Mario Andrada at a briefing Wednesday, where it was also revealed that travel grants for the National Olympic Committees had not been arranged.
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Sparsely populated venues have been a familiar sight at the Rio Olympics and Andrada conceded the total sold for the Paralympics was "a concern."
He added: "However, we understand that the rhythm of sales for Olympic tickets have picked up dramatically and generally in the history of the Games the energy generated by the Olympic Games tends to help a lot in selling tickets for the Paralympics. That's what we are working on."
The London 2012 Paralympics attracted a record 2.7 million spectators.
This year's event begins on September 7.