He was in his seventies, the DI estimated, but still a strong man both in physique and temperament. Wiry grey hair covered a big head, his craggy face lined with a lifetime’s exposure to the elements. A baggy brown suit, with an old-fashioned waistcoat, covered a collarless flannel shirt fastened at the neck with a brass stud.

‘What about this young fellow?’ growled Crippen, staring at the youth, who lurked at the edge of the group.

‘That’s Shane Williams,’ said the coroner’s officer. ‘Sort of an apprentice mechanic. He was the first to find the body.’

The lad shuffled uneasily. ‘I’m not a proper apprentice,’ he mumbled. ‘Just working here, while I’m waiting to be called up for National Service.’

For the next five minutes the detective inspector dragged what little information he could from the four men about their scanty knowledge of ‘the occurrence’, before going towards the barn to look at the scene. Billy Brown and his sergeant walked each side of him as they went up to the big Fordson, where the coroner’s officer carefully removed the tarpaulin and put it to one side.

‘They shouldn’t really have put this on,’ he said. ‘But I suppose they didn’t want to leave him exposed until we came.’

Arthur Crippen stood for a long moment looking at the scene.

The tractor was on an almost even keel, its offside back wheel resting squarely on the neck of the corpse, the head hidden by the massive tyre. A few spanners lay scattered around, amid the rough wooden blocks, which appeared to be sections sawn from a railway sleeper.

‘Why shouldn’t it be an obvious accident, guv?’ murmured Sergeant Nichols.

‘Bloody daft thing to do if you’re a proper mechanic, putting your head under a jacked-up wheel!’ objected Billy Brown, who felt obliged to justify his calling out the CID.