The captain's armband that Cristiano Ronaldo flung to the ground in disgust after Portugal were denied an injury-time winner against Serbia was sold at a charity auction for 64,000 euros ($75,000) to an anonymous bidder.

With seconds to go while the score in the 2022 World Cup qualifier was 2-2 in Belgrade, Ronaldo thought he had netted the crucial goal, when the ball appeared to cross the goalline before Stefan Mitrovic cleared.

But without video technology in use, the goal was not awarded.

A fuming Ronaldo received a yellow card for his protests and at the final whistle, as he stormed from the pitch, he threw his captain's armband to the ground.

Djordje Vukicevic, a local firemen who was deployed at the stadium, picked it up and immediately contacted a regional sports channel with the idea of auctioning it for charity.

Vukicevic told AFP on Tuesday that he suggested raising funds required to treat a six-month-old baby, Gavrilo Djurdjevic, who suffers from a rare disease.

The infant is battling spinal muscular atrophy, a disease which affects about one in 10,000 births, and results in death or the need for permanent ventilation by the age of two in 90 percent of cases.

After the sports channel Sportklub verified the item's authenticity by checking post-match photos and videos, they teamed up with a charity organisation and put Ronaldo's armband up for a bidding contest on auctioning website Limundo.com.

The 64,000 euros gathered at the auction represents only a fraction of the amount needed for the baby's treatment, as his hopes are pinned on the "world's most expensive drug", the treatment that costs around two million euros ($2.36 million).