Christopher Lee and Britt Ekland had the splashier roles in The Wicker Man, the 1973 occult horror set in a fictional Hebridian island demented by paganism, but it was the performance of Edward Woodward, who died today, that made that film so haunting. Woodward was cast in the role of devout Christian police sergeant Neil Howie, dispatched from the mainland to investigate the disappearance of a young girl, after actors including Michael York and David Hemmings turned it down.

It's hard to imagine how slick, pin-up performers as these would have brought the same emotional punch to that terrible, awe-inspiring climax, in which Howie hollers to God and sings The Lord Is My Shepherd as he is immolated. It's one of the most truly appalling sequences in cinema.

But much of the scene's power is all about the actor: after spending the whole of the film in such upstanding, even self-righteous bafflement, his clear-eyed terror make this a deeply moving conclusion – unusual for a horror that had more than a touch of the Hammer to it.

Woodward specialised in righteous enforcers: men of honour, grappling with temptation; men to trust and respect, and not to get on the wrong side of. He shares more with the likes of The Conversation-era Gene Hackman than, say, the stars of The Sweeney. A lot of these clips have a saxophone-friendly langour to them; they also show Woodward alone, with his thoughts – here was a man who didn't need a lot of back-up to make a scene compelling.

When The Wicker Man was released, Woodward was already well-known in the UK as rebellious TV spook Callan, a role he played from 1967 to 1972. Here he is strengthening his fists while resisting the bottle.

And here he is, failing to resist as he rails against the death of a colleague.

There's a wonderful moment about two minutes in, when Callan, stumbling with grief and booze, says: "If one of us cracks, we all could. Because there is an ugly black streak, bloody deep, and it's welling up in the likes of us, and holding it down is what makes us good at our jobs. That's all." It could be a statement of intent for all of his characters.

The Wicker Man had not, at the time, reached cult classic status – it was the 1980 Australian film Breaker Morant, in which Woodward played the title role as the drover, horseman, poet and soldier sentenced to death for his part in the summary execution of several Boer prisoners and a German missionary, which first brought him to international attention.

But it was Woodward's role in 1980s CBS series The Equalizer that cemented his fame. Then in his 50s, the actor played a former secret agent who strives to atone for past sins through the gratis offering of services as a troubleshooter, protector and investigator. New York was a world away from the homespun locations and wobbly production values of his previous cop roles, but Woodward brought with him the same blend of earnestness, cynicism and thoughtfulness.

The show paced itself around its star, finding focus in his stillness. Here was a man who didn't need his gun to make a point; who wasn't afraid to sing, alone, at night, nursing a scotch.

Woodward was, in fact, a prolific singer, recording 12 albums of songs, as well as three of poetry. Here he is, perfectly balancing the emotion and enunciation on this They Didn't Believe Me.

You can feel his training here – he became Rada's youngest ever student when he was admitted aged 16. After graduating, he became a respected stage actor, with seasons in the West End, at Stratford, on Broadway and at the National under Laurence Olivier.

But it wasn't all training. To all Woodward's performances, there's a fundamental truthfulness that shines through. When he was five, he won a talent contest in Wallington, for which he was awarded a penknife. But it wasn't long before the silver coating began to peel, revealing some far more mundane metal beneath. "You start doing deals with Americans," he once said, "particularly the big Hollywood ones, and you'll appreciate the story about the silver penknife."

Despite a triple heart bypass in 1996, and a prostate cancer diagnosis in 2003, Woodward was still working until very recently.

In 2007 he had a funny cameo in Simon Pegg's comedy Hot Fuzz, a mildly Wicker Man-inspired comedy about the sleepiest town in the country, plagued with an alarmingly disproportionate accident rate.

Then there was an episode of The Bill from 2008, possibly an inspiration for Michael Caine's elderly vigilante drama Harry Brown.

And, from March this year, he spent a couple of months on EastEnders, playing Tommy Clifford, another old soul atoning for past sins (in this case the accidental killing of Patrick Trueman's fiancee).

In an interview in March this year, Woodward revealed that on his first day on the set of EastEnders he embarrassed himself (in his words) by throwing his arms round Pam St Clement and asking her how she was. "As I walked away, I realised I'd never met her before in my life. Because I watch EastEnders I, like any other viewer, think I know these people."

That seems to sum up the humility of the man; a humility (and a humour) much in evidence in this clip of his opening a village fete in Cornwall, gently awarding some pint-size carnival queens their trophies.