5 photos: Rio Olympics: Torch arrives ahead of 2016 Games 5 photos: Rio Olympics: Torch arrives ahead of 2016 Games Brazilian president Dilma Rousseff lit the Olympic torch in Brasilia Tuesday. (CNN) The participation of 23 athletes in the Rio Olympics could be under threat, after doping samples gathered from London 2012 tested positive for banned substances. Hide Caption 5 of 5"All athletes found to have infringed the anti-doping rules will be banned from competing at the Olympic Games Rio 2016." Russia's track and field athletes are currently banned from international competition , a sanction which could prevent their participation in Rio 2016. Hide Caption 3 of 5 5 photos: Rio Olympics: Torch arrives ahead of 2016 Games The Olympic flame arrived on its own private flight form Switzerland.

Source: CNN May 27, 2016 08:22 UTC