Michael Clarke Duncan: Character actor best known for his role in 'The Green Mile' hard-hitting TV documentaries

Character actors, lacking stars' power to twist a project to suit themselves, have a tricky negotiation with their physical natures: a distinctive look can attract attention, but too much of it can lead to typecasting and a narrowing of opportunity.

At 6ft 5in, Michael Clarke Duncan, might have expected to spend his life playing heavies, jocks and similar roles but the prison drama The Green Mile brought a meatier part and well-deserved Oscar and Golden Globe nominations. It pushed his career to a different level but also in new emotional directions, moving him from a threatening presence to a more benign one – which was more in line with his own personality – and eventually he was even able to play his bulk for laughs in films such as Talledega Nights (2006).

Six year-old Duncan and his 10 year-old sister Judy were abandoned by their father and brought up by their his mother, who worked as a cleaner. She resisted his desire to be a football player but while his sporting ambitions were met with basketball at Kankaffee Community College, he developed a taste for acting and studied communications at Alcorn State University. At the same time he was helping support the family – his mother was by now ill – with stints as a bouncer and a ditch digger.

His acting ambitions took him to Los Angeles where he became a private bodyguard for stars Will Smith, Jamie Foxx and others. However after the murder of rapper Notorious BIG in 1997 he gave up the work to concentrate on developing his acting career.The contacts he had made proved useful and he landed small roles in Ice Cube's slacker comedy Friday (1995) and his 1998 comedy thriller The Players Club, as well as a 1996 episode of Will Smith's TV series The Fresh Prince of Bel Air.

But these early roles often continued the life he had left, as he played bouncers, bodyguards and heavies – sometimes credited as Michael "Big Mike" Duncan. The biggest of these was in Warren Beatty's political satire Bulworth 1998. In 1998 his first major break came with Armageddon, about a Nasa mission to save earth from an asteroid. The star, Bruce Willis was impressed enough to recommend Duncan to Frank Darabont, who was casting his adaptation of Stephen King's depression-era redemption story The Green Mile.

Duncan played the giant but child-like John Coffey, an innocent man with extraordinary healing powers, on death row for raping and killing two young girls. While in prison he finds and punishes the real killer and exacts revenge on a sadistic guard. At the end, exhausted by life's griefs, he goes calmly to the electric chair, refusing the proffered hood, as he is afraid of the dark. Duncan brought an extraordinary tenderness to the portrayal, balancing strength and tenderness, fear and determination, and easily matching the star, Tom Hanks.

It was a role so perfectly suited to Duncan's appearance and temperament that he would never find anything quite to match it. Nevertheless, it boosted his career, not least as he appeared in three more films with Willis: Breakfast of Champions (1999), Alan Rudolph's chaotic and widely panned adaptation of Kurt Vonnegut's novel; the weak comedy The Whole Nine Yards (2000), and the stylish noir comic book adaptation Sin City (2005).

Meanwhile, with a rich and gravelly voice as distinctive as his looks Duncan developed a career as a voice artist – a good way of increasing his range and avoiding audiences tiring of him. He was in several animated films, including an Old English Sheep Dog in Cats and Dogs (2001) and the sequel The Revenge of Kitty Galore (2010), as well as Dinotopia (2005) and Kung Fu Panda (2008).

On screen, his size made him a natural for Tim Burton's remake of Planet of the Apes (2001), playing the gorilla Colonel Attar to Tim Roth's chimpanzee General Thade. He was similarly imposing as the Nubian King Balthazar in the same year's Scorpion King. To play the crime lord Wilson Fisk (aka Kingpin) in Daredevil (2003), he added another 40 pounds to his already massive frame. By 2005 Duncan was able to dominate the screen and his impact in the dystopian The Island – directed by Armageddon's Michael Bay – was far beyond his limited screen time.

In 2009 Duncan became a vegetarian, and in a film he made for Peta he spoke lovingly about his large collection of pets and explained how, when he changed his lifestyle, he gave away the $5,000 worth of meat that was in his fridge. The following year he met the Apprentice and Celebrity Apprentice alumna the Rev Omarosa Manigault in a Whole Foods shop and they became engaged.

His last strong film role was in 2010, in Mario Van Peebles' country music- driven Redemption Road. It had something of the flavour of The Green Mile and Duncan brought a subtle ambiguity to his portrayal. The following year he landed a recurring role as a lawyer turned bar-owner in TV's The Finder.

But it is for The Green Mile that Duncan, who died following a heart attack in July, will rightly be remembered. His co-star Tom Hanks and the director Frank Darabont paid tribute to him both as an actor and a man, the director describing him as "the gentlest of souls – an exemplar of decency, integrity and kindness."

John Riley

Michael Clarke Duncan, actor: born Chicago 10 December 1957; died Los Angeles 3 September 2012.