The tone of the book is set by the cover, which has the look of a red top tabloid.The title, Blood Rites, is written in inch high capital letters in white and black across a red banner, with the red splattering and dripping down into the word 'BLOOD'. A stamp on the front states: "WARNING. CONTAINS EXPLICIT MATERIAL". If the voyeuristic reader has not yet been enticed to buy this new paperback, they need only turn to the back to read (in big red capitals): WELCOME TO THE WORLD OF RITUAL SACRIFICE. It explains: "Around the world, humans are bring trafficked, kidnapped, sold and enslaved, for the specific purpose of sacrifice…. Voodoo priests in London have been linked with ritual murders. And a recently leaked police commissioned report found that witchcraft, voodoo-related abuse and murder, are rife in the UK…" Really?

Blood Rites purports to be a serious attempt to describe and explain the practice of human sacrifice around the world in the context of a belief in witchcraft and Voodoo, through history and still occurring today.

The problem with this is that it fails to distinguish between fact and fantasy and mixes true recorded criminal cases, for which there is evidence, with myths and legends for which, by definition, there is not.

The book claims to be a serious journalistic investigation into ritual killings intended to stimulate debate. But it loses credibility with its sensational and titillating tone. For instance, the introduction concludes: "Are you ready to hit the blood-soaked road to Hades? And find out what deadly craziness Homo sapiens can sink to?" The author himself is proud to announce that his coverage is "at times unconventional and outrageous," hallmarks of the so-called gonzo journalist which he claims to be.

Shreeve believes he is well qualified to write about witchcraft and Voodoo because of his own previous experiences, dabbling in the occult and "magick" which he describes as "the art of manipulating reality to your own ends". As an "apprentice" to a Trinidadian Voodoo doctor called Earl Marlowe, he learnt about fortune telling, sorcery and how to cast spells. In another guise as 'Doktor Snake' Shreeve is the author of Doktor Snake's Voodoo Spellbook, in which he chronicles his time with Marlowe with whom he used to play in a band in London during the 1980s. In Blood Rites, he puts himself centre stage in the gonzo tradition.

Shreeve began his research after the horrific discovery of a headless and limbless body, which came to be known as 'Adam', in the River Thames in 2001. In the midst of recording this journalistic investigation Shreeve writes how he joined a friend, a Canadian shaman called Dr Crazywolf, to perform a ceremony on Hampstead Heath to "set Adam's soul free". In another bizarre episode he describes a fictional encounter in a London pub with Beat Generation writers William S. Burroughs and Allen Ginsberg (both of whom, he concedes, are dead) and relates an imaginary conversation about the need for scepticism when writing about stories of rituals and black magick rites. (Shreeve would have benefited from this advice when writing Blood Rites). Whilst these are no doubt clever gonzo moments they undermine the credibility of the book as a work of serious, accurate, evidence-based investigative journalism.

This is worsened when Shreeve reports – as a mere postscript in two pages at the end of the book – allegations which surfaced last year that 300 African boys had been trafficked to the UK and sacrificed in African churches in London. The claims were made in a report commissioned by the Metropolitan police investigating the cases of Adam and two African girls who had been tortured, (in the case of Victoria Climbie, to death) by carers who believed they were witches, possessed by evil spirits.

Immediately after the report was leaked and sensational headlines screamed: "Children sacrificed in London churches", the police issued a statement stating categorically there was no evidence for these claims. But Shreeve does not report this. He says merely: "It was said these particular aspects were speculation and hearsay." And yet the blurb on the book and in the press release sensationally highlight these totally discredited allegations as fact, without question. Undeniably, there have been real, recorded cases of human sacrifice around the world throughout history. They certainly continue today. Sadly Shreeve fails to analyse, with any convincing accuracy, the scale of it.