HE was likened to a volcano rumbling under the surface – and when the crust cracked, the eruption was uncontrollable.

Pop group manager John Theron knifed band member John Jones to death after discovering that he had been bedding his wife, Sue – the last and ultimately tragic chapter in their stormy relationship.

Twice he forgave her affairs but then he found her sitting on a settee with Jones, lead guitarist with the Stonehenge pop group he managed. Theron lost control and armed himself with a knife.

“You had better hurry up and get round here, he’s going mad,” his wife of six years pleaded with the police in a dramatic 999 call.

But it was too late. Still on the line, she saw Jones stumbling towards her, clutching his stomach and gasping ‘God, Sue, he’s got me’.

Theron then plunged the knife into his wife but she survived.

She said: “I don’t remember him stabbing me. All I can remember is just feeling hot blood pouring out of me.”

Mrs Jones told Winchester Crown Court jurors how Theron had earlier blown the whistle on her husband’s fling with his wife.

“He knocked on my door and told me my husband was down his house having an affair with his wife,” she said.

Mrs Jones tried to calm him down but he was “mad”.

Theron told her: “I’m going to kill them both.”

Theron, 44, from Leigh Park, Portsmouth, denied murdering 33-year-old Jones, attempting to murder his wife and wounding her with intent to cause grievous bodily harm.

Following legal argument on the third day of his trial in 1976, he changed his pleas and admitted manslaughter and wounding.

“This is a tragedy with one of the oldest plots in the world,” lamented Mr Justice Ackner, imposing a five-year jail term.

“A jealous husband, many years older than his young and amorous wife, kills the suspect lover and nearly kills his wife.”

Likening Theron to the simmering volcano, his barrister David Owen Thomas said Theron realised that there was no future in the marriage.

Shortly after the guitarist’s death, the band broke up.