Watch the Official Movie Trailer for 'Richie McCaw Chasing Great'

A film is being released about All Black legend Richie McCaw, showcasing his life from his beginnings in the small town of Kurow through to a rugby superstar leading the national team to two World Cup victories.

Chasing Great, released in cinemas in September, will showcase never-before-seen footage of McCaw including his friends and family.

"I was always quite keen to make sure I kept some of the private stuff private, not for any reason other than I just felt that was the right thing to do," McCaw said.

He said the opportunity to "inspire some young kids" saw him take part in the project.

The film, directed by Michelle Walshe and Justin Pemberton also features a cover of the track Everybody wants to rule the world by Lorde.

This is a film for New Zealanders young and old, it will really connect with anyone interested in what it takes for an ordinary person to achieve phenomenal accomplishments," Ms Walshe said.

The film opens in cinemas on September 1.