A letter written by Albert Einstein rejecting religion has been sold at auction for over £2 million.

Known as the “God letter”, the message, written by the world-famous scientist in 1954, was expected to fetch around $1.5m (£1.2m) at an auction at Christie’s in New York on Tuesday, but instead sold for almost double, at nearly $2.9m (£2.3m).

The letter, described by Christie’s as a “remarkably candid, private letter”, which “remains the most fully articulated expression of his religious and philosophical views”, was written a year before the Nobel Prize winning physicist died.

Written in Einstein’s native German, it was sent to Eric Gutkind, the philosopher, in response to a book the latter had written called Choose Life: The Biblical Call to Revolt.

In the one-and-a-half page letter, Mr Einstein, who was 74 at the time, identified himself as a proud Jew but dismissed Judaism as a religion, referring to it as being “like all other religions, an incarnation of childish superstition.

"The Jewish people to whom I gladly belong, and in whose mentality I feel profoundly anchored, still for me does not have any different kind of dignity from all other peoples.

“As far as my experience goes, they are no better than other human groups, although they are protected from the worst cancers by a lack of power. Otherwise I cannot see anything ‘chosen’ about them.”

The theoretical physicist also wrote that “the word God is for me nothing more than the expression and product of human weaknesses, the Bible a collection of honourable, but still primitive, legends which are nevertheless pretty childish.”

The letter, which was found among Mr Gutkind’s papers, previously came up for auction in London in 2008, when it was sold for £170,000.

Christie’s auctioned off another rare letter from the scientist, to his sister Maja, in May, while last year another note he had written, describing his theory on a happy life, was sold for £1.19m at an auction in Jerusalem.