A Victorian man’s pocket guide to London’s prostitutes – disguised as a wallet – has sold for more than 13 times its estimate of £300.

The Man Of Pleasure’s Illustrated Pocket-Book For 1850: A Complete And Gentlemanly Night Guide, London, went under the hammer at Hansons’ Fine Art & Library Auction on Thursday.

It was bought by a private UK buyer for £4,000.

The 169-year-old book includes 50 sketches and describes prostitutes using coded language and makes use of equestrian and sea-faring references.

Man Of Pleasures pocket guide (Hansons/PA)

The guide was initially sent to Hansons’ books expert Jim Spencer for a free valuation and was estimated to sell for £300.

Mr Spencer said: “It’s an amazing result that’s exceeded expectations. Antiquarian books of this nature do seem to do very well. Early erotic publications are sought-after by collectors, both nationally and internationally.

“Books such as this were published and sold in secret at a time when they were regarded as obscene. The fact that this latest find was disguised as a wallet speaks volumes about its content.”

Another section of the book entitled The Health Of The Man Of Pleasure includes prescriptions and descriptions of sexually transmitted diseases.

Wallet containing The Man Of Pleasure’s Illustrated Pocket-Book (Hansons/PA)

A page on “gonorrhoea or clap” advises drinking a pint of water containing linseed and sugar or lemon and also advocates barley water or thin gruel to offset the symptoms.

Mr Spencer said he believes he has a “knack for unearthing centuries-old erotic literature”.

As well as the Victorian wallet find, he discovered a 300-year-old sex manual from 1720 which sold for £3,100 from an estimate of £80-£120.

This was followed by Memoirs Of The Life Of Miss Fanny Hill, The Career Of A Woman Of Pleasure, from 1749, which sold for £360 from an estimate of £40-£60.