A new documentary reveals the mystery behind a vicious crime that took the life of UK historian and antiquarian book dealer Adrian Greenwood last April.

Greenwood's body was found in his Oxford home with 30 stab wounds by his house cleaner. Missing from his book inventory was a £50,000 first edition of Kenneth Grahame’s 1908 children’s classic The Wind In The Willows in its original dust jacket.

Oxford-educated Greenwood, 42, had gained a reputation for selling early editions of Harry Potter and a Banksy work.

The documentary follows police as they unravel the murder and arrest debt-ridden Michael Danaher for the crime. Down-and-out Danaher possibly meant to sell the rare book on eBay, according to reports.