Children in US schools are being taught the Loch Ness monster is real, and its existence disproves Darwin's theory of evolution.

The students attend privately run, fundamentalist Christian schools which teach creationism – the idea that the entire universe was a creation of God's will – rather than scientifically accepted evolution.

Other claims in the book include the belief that dinosaurs were fire breathing dragons and that a Japanese whaling boat once caught a dinosaur.

The bizarre claim in the schools' textbooks stems from a desire to explain the millions of years Earth existed that the Bible doesn't account for if a literal interpretation of the Bible is applied.

The schools believe that if it can be proved that man once walked the Earth with dinosaurs, then Darwin's theory of evolution will be disproved.

The books are produced by Accelerated Christian Education.

"Have you heard of the Loch Ness Monster in Scotland?" the book asks, "'Nessie' for short has been recorded on sonar from a small submarine, described by eyewitnesses, and photographed by others. Nessie appears to be a plesiosaur."

The revelations about what kids are being taught have sparked anger across the US, especially because the classes are partly publicly funded.

Bruce Wilson, a professor who specialises in the US far-right, says these teachings are typical of Christian fundamentalism.

"One of these texts from Bob Jones University Press claims that dinosaurs were fire-breathing dragons. It has little to do with science as we currently understand. It's more like medieval scholasticism," The told The Scotsman.

"The majority of parents now home schooling their kids are Christian fundamentalists too. I don't believe they should be publicly funded, I don't believe the schools who use these texts should be publicly funded."

Jonny Scaramanga, a former student who now spends his time speaking out against fundamentalism says teachers rewrite history to suit their religious beliefs.

"The reason for that is they’re saying if Noah's flood only happened 4000 years ago, which they believe literally happened, then possibly a sea monster survived.

"If it was millions of years ago then that would be ridiculous. That's their logic. It's a common thing among creationists to believe in sea monsters."