Richie McCaw has been hailed as one of the game's greatest ever players whose achievements are "nothing short of unbelievable" following the New Zealand captain's decision to retire.

McCaw called time on his playing career at a press conference in Wellington on Thursday, his announcement coming less than a month after becoming the first captain to lift the World Cup twice.

The 34-year-old flanker also leaves the game with a record 148 international appearances, three World Player of the Year awards and the respect and admiration of teammates and opponents throughout the sport.

Former South Africa skipper Jean De Villiers, who announced his own Test retirement earlier this year due to injury, said on www.sarugby.net: "We all know that at some stage we will have to hang up our boots and say goodbye to this game we love so much.

"All we then have left are memories and Richie can be immensely proud of the memories he has helped create on and off the field.

"He has been superb and what he has achieved on the field, as an individual and as captain of the All Blacks, is nothing short of unbelievable.

Richie McCaw chats to Jean De Villiers© David Rogers/Getty Images

"As a fierce competitor it pains me to say it, but you'll probably go down as one of the best ever and those memories will last for your entire life," De Villiers added on www.stuff.co.nz.

Conrad Smith, who was part of the New Zealand side that lifted back-to-back World Cups, said it had been "a pleasure" to have played alongside McCaw.

The Pau-bound centre said: "You've shaped the All Black team in a way that is modelled around you, your dedication, your hard work and all the success we've had in that time you've been part of.

"Congratulations on the announcement, I know you have plenty of success to come in different fields so I look forward to seeing it all and following it closely."