Muhammad Ali

The Jamaican sprint superstar has won gold in the 100 metres, 200m and 4x100m in each of the past three Olympics, firmly cementing his status as one of the greatest athletes in history.

Now 30 years old, Bolt is planning to step away from the sport following the World Championships in London in 2017 and his new film, 'I Am Bolt', is due to be released later this month - a behind-the-scenes documentary looking at his preparations for Rio 2016.

Bob Gunnell said in a statement that Ali's condition was fair, a brief hospital stay was expected.

RNZI reports former heavyweight world champion Ali, 74, has been suffering from Parkinson's disease for more than three decades.

Ali, who lives in Phoenix, Arizona, has suffered some health problems in recent years.

He was admitted to hospital in December 2014 with what was believed to be a mild case of pneumonia.