Dr Stephen Shapiro, an expert in cultural studies, race and slavery, accused the author of using the novels to make racial prejudice innocent - by presenting bigotry through a fantasy world.
Speaking just days before the film of The Two Towers, the second part of the classic series, opens across the UK, Dr Shapiro said the books represented anxieties about immigration in mid-1950s Britain.
The academic claimed: "Put simply, Tolkien’s good guys are white and the bad guys are black, slant-eyed, unattractive, inarticulate and a psychologically undeveloped horde."
His comments were attacked by Harper Collins, publishers of the trilogy, and the Tolkien Society, who insisted the writer was not a racist.
Dr Shapiro said that in the trilogy, a small group, the fellowship, is pitted against the onset of a foreign horde. This reflected long-standing Anglo-European anxieties about being overwhelmed by non-European populations, he added.
While Tolkien describes the Hobbits and Elves as amazingly white, ethnically pure clans, their antagonists, the Orcs, are a motley dark-skinned mass, akin to tribal Africans or Aborigines. The recent films amplified a "fear of a black planet" and exaggerated this difference by insisting on stark white-black colour codes, Dr Shapiro insisted.
He said: "Tolkien wrote The Lord of the Rings because he wanted to recreate a mythology for the English that had been destroyed by foreign invasion. He felt organic English culture had been destroyed by the Normans. There is the notion that foreigners destroy culture and there was also a fantasy that there was a solid homogeneous English culture there to begin with, which was not the case because there were Celts and Vikings and a host of other groups."
The trilogy even racially stereotypes the Scots, according to Dr Shapiro.
He added: "One can read the book as a kind of ideal of Great Britain. For instance, the dwarves were his notion of what Scots were like. It is like a southern England clich of a dour, muscular race and that represents the Scots in the book.
"We have a pure village ideal which is being threatened by new technologies and groups coming in. I think the film has picked up on this by colour coding the characters in very stark ways.
"For instance, the fellowship is portrayed as ber-Aryan, very white and there is the notion that they are a vanishing group under the advent of the other, evil ethnic groups.
"The Orcs are a black mass that doesn’t speak the languages and are desecrating the cathedrals.
"For today’s film fans, this older racial anxiety fuses with a current fear and hatred of Islam that supports a crusading war in the Middle East. The mass appeal of The Lord of the Rings, and the recent movies, may well rest on racist codes."
Dr Shapiro said that the trilogy, begun in the 1930s and published in the 1950s, was written at the onset of decolonisation, when the first mass waves of immigrants from the Caribbean and Indian sub-continent came to Britain. The Midlands, Tolkien’s model for the Shire, was becoming a multicultural region.
Barry Clarke, a spokesman for Harper Collins, said Dr Shapiro had got his dates mixed up.
He said: "The copyright for The Fellowship of the Ring, the first in the series, was 1954. Tolkien would have finished writing the book quite a bit before the mid-50s and certainly the idea would have come a number of years before, given the sheer size of the book - so I think the timing is out.
"A number of academics have commented on Tolkien’s work and this is the first time anybody has ever seen these issues in it. Of course, if one looks hard enough at many great epics, you can extrapolate what you like out of it, particularly if you have academic kudos behind you."
He added: "A number of people have said that they think The Lord of the Rings could be an allegory for the Second World War or indeed the first, as Tolkien fought in it, but it was never a view that he agreed with. His great abiding passion and interest came from the Icelandic saga’s and mythology, and this was his version of one of those sagas."
Richard Crawshaw, a trustee for the Tolkien Society said: "There was definitely no racial intent in his work. He detested racism."
The Two Towers opens in the UK next Wednesday.