A feature-length documentary centred on recorded conversations of boxing champion Muhammed Ali is being led by a former Who Do You Think You Are? director.

I Am Ali is the feature debut of Clare Lewins, who has previously directed episodes of British TV series Countrywise, Perspectives and Who Do You Think You Are?.

Financed by Universal Pictures, the film has been made by Lewins’ Fisheye Productions and Passion Pictures, which has made hit documentaries such as One Day In September and Fire In Babylon and executive produced award-winners Searching for Sugar Man and The Imposter.

Executive producer John Battsek told Broadcast sister publication ScreenDaily: “It’s a film built around phone conversations that Ali recorded for many years with his family. That’s the spine of the film.

“It’s a very personal perspective on Ali, from Ali – in a way – through a 20-year period of his life when he was still fighting.”

Battsek told delegates at Sheffield Doc/Fest that Leon Gast’s 1996 film When We Were Kings was the inspiration for his move into documentary. The film told the story of the 1974 heavyweight bout in Zaire – the Rumble in the Jungle – between champion George Foreman and underdog challenger Ali.

Passion was in Sheffield with Nick Ryan’s mountaineering doc The Summit, which played on the opening night having previously premiered at Sundance where it won the World Cinema Award.

Projects in development and production from Passion include Amir Bar Lev’s Happy Valley, which focusses on the Penn State/Jerry Sandusky scandal for A&E IndieFilms, and The Great Invisible, about the effects of the BP oil spill on the Gulf Coast, directed by Margaret Brown that is in the late stages of post-production for Participant Media.

Passion recently co-produced narrative feature How I Live Now, starring Saoirse Ronan and directed by Kevin MacDonald for Film4 and the BFI, which is due for UK theatrical release later this year.

It is also making The Green Prince with Simon Chinn of Red Box, the story of Mosab Hassan Yousef, the son of one of the founders of Hamas, who risked everything as a young man to become an Israeli spy. It will be sold by Global Screen.