The smash hit Dan Brown conspiracy thriller The Lost Symbol has sold 550,946 copies in the first five days the book has been on sale, according to Nielsen BookScan.

The sequel to Brown’s The Da Vinci Code has smashed the previous hardback record held by Thomas Harris’s Hannibal, which has sold 299,000 copies since 1999.

Sales have reportedly been helped by retailers slashing the cover price to £8 — under half the £18.99 recommended retail price — adding up to sales of £4.6 million.

Despite its runaway early success, the book is still is nowhere near matching that of The Da Vinci Code - 81 million copies sold around the world and the UK’s biggest-selling paperback of all time.

In all, The Lost Symbol last week took 13p of every pound spent in UK book retailers.