Rio 2016: Top class athletes are competing on the world stage, so what’s with all the empty seats at the Olympics?

IT came as a shock to see so many empty seats during the Rio 2016 opening ceremony, but no-one expected the problem of unfilled venues to persist once the Games began in earnest.

was back at the height of his powers on Sunday, but his straight-sets victory in the first round of the men's singles tennis was only viewed by a paltry crowd of spectators.

And it's not just the tennis which was affected. Over the weekend, no more than 500 people attended the boxing, while the beach volleyball court on Rio's Copacabana beach was only 20% full when the players walked out on court.

Even the gymnastics, one of the most perennially popular Olympic events, and the football, Brazil's biggest sport, were hit by the curse of the empty seats.

So why is this still happening?

Firstly, the tickets haven't all been sold yet. As of Monday morning, organisers say 84% of of the 7.5 million available tickets have been sold, as well as only 29% of the 2.5 million tickets for the Paralympics.

The Olympic committee's excuse has been that South Americans are very late buyers - but maybe they just haven't been convinced by the thrills of the Games. Tickets are expensive and the organisers have found it difficult to convince Brazilians that the Games they've paid for have been worth the money.

The situation has got so desperate that appeared in adverts over the weekend urging Brazilians to buy tickets.

Meanwhile, many international fans have stayed away from Rio after scares of anti-government protests, crime, and the Zika virus. If stars such as decide not to attend the Games because of the potential danger, then why should people go to spectate?