Muhammad Ali made an emotional return to the Olympic Games as he took part in the opening ceremony on Friday.

The three-time heavyweight world champion and gold medallist had the honour of carrying the Olympic flag into the stadium alongside names such as long-distance running legend Haile Gebrselassie and United Nations Secretary General Ban Ki-Moon.

The group of flag bearers met Ali near the end of their route, and paused to have him join the ceremony and touch the flag.

Muhammad Ali stood, tentatively, and took in applause as his wife, Lonnie, supported him. She appeared to say "Wave, Muhammad" as the crowd rose to acknowledge the boxing superstar.

Ali once again left an indelible mark on an Olympic Games despite his growing frailty, in similar fashion to his iconic appearance lighting the Olympic torch in Atlanta in 1996.