A card from Jack the Ripper has sold for more than £20,000 at auction.

East London Advertiser: The letter, addressed to Ealing Police Station. Picture: Grand Auction LtdThe letter, addressed to Ealing Police Station. Picture: Grand Auction Ltd (Image: Archant)

The letter from the Whitechapel killer was sent to Ealing Police in October, 1888, where it sat in police files until 1966 when it was gifted to a retiring PC.

The constable’s widow approached Grand Auctions with the card, which exceeded its £600 - £900 estimate by going for £22,000 at auction on Monday.

Jonathan Ridley, the historian who dealt with the card, said: “A card like this has never gone up for sale before, so the estimate was a complete guess, not based on scientific fact.

“The widow rang me up and said I’ve got a card from Jack the Ripper, which I didn’t believe at first, but after talking I realised she was genuine. It’s in good condition for its date.”

Much of the auction was conducted through a confidential bidding platform, so it’s unknown how many bids the winner placed. Jonathan believes around 40 were placed in total, with the victor being a private British collector.

The letter, which is written in ink, reads: “Beware there is two women I want here they are bastards and I mean to have them my knife is still in good order it is a students knife and I hope you liked the half of kidney. I am Jack the Ripper.”

There is a pencil date on the front, written by officers, of October 29 1988. Mary Jane Kelly, the last of the five women murdered most believe were killed by the Ripper, was murdered 11 days after the card was received.

The kidney mentioned in the card refers to another Ripper letter, in which the writer states he fried and ate the kidney of one of his victims.

Jonathan said: “I studied the Whitechapel area and the population boom around the Industrial Revolution, so was particularly interested in this item. The question is, why was he so famous, of all the killers? It’s because the first two letters which were published, which gave Jack the Ripper his name, were actually written by a journalist to boost publicity.”

Including the auction premium, the bidder will pay £30,000 for the letter.