Black spots appeared on some medals just months after were distributed in Brazil
More than 100 medals have been returned to Rio Olympic organisers due to rusting and the development of black spots.
A spokesperson for the Games on Friday told Reuters that the issues were "completely normal" when they first came to light last October. Approximately 130 medals - mostly bronze - are being fixed by the Brazilian Mint, who were the manufacturers of the medals.
"The most common issue is that they were dropped or mishandled and the varnish has come off and they've rusted or gone black in the spot where they were damaged," spokesperson Mario Andrada explained.
"The second thing is that a small few, about 10, had problems with the extreme cold."
In total, 2,488 were produced for the Rio Olympic Games. In the case of silver and bronze medals, manufacturers used 30% recycled materials.
An Olympic gold medal from last summer's Games in Rio, won by the Fijian rugby team. Mostly bronze medals were affected by rusting. Image: PA Images