'There was a lot more going on. They've made a mistake': Mark Alexander was jailed for killing his father and burying him in concrete... but now, speaking from his cell, he reveals startling new evidence that could set him free ⊕

A body entombed in concrete, an overbearing father and a rebellious son with a glamorous yet 'unsuitable' lover - plus a coterie of curtain-twitching neighbours in the heart of the English countrysid…