Highly confidential police information for prosecutors’ eyes only was faxed in error to a Harrow shop in a massive blunder.

Sagar Ceramics in Pinner Road received a copy of a police national computer file that listed the previous convictions, aliases, addresses and other personal details of a seasoned criminal.

The 14-page document contained no cover sheet or sender information but did include a handwritten note at the top of the front page that mentioned the defendant was to be sentenced at Harrow Crown Court on Friday.

The file warned: "This printout is produced for the use of prosecutors only and must not be disclosed to any other party.

"Keep the data secure and protect them against loss or unauthorised access."

Sunil Shah, owner of Sagar Ceramics, was not surprised to find yet more private police records lying in his fax machine’s in tray.

He said: "This is the third time we have got it and every time it comes on my fax machine, I’ve destroyed it, since there’s no number to contact and I thought it came by mistake.

"It’s all the cases and all the personal details, people’s names and offences and what court they have got to go to.

"This is somebody’s details. This is protected data that should not be sent to me. How would you like your details given to everybody?"

Fortunately, the Observer was able to intervene and alert the authorities to the mistake.

A Metropolitan Police spokeswoman said: "It has been brought to our attention this information, intended for the police liaison officer at Harrow Crown Court, appears to have been faxed to a shop in Harrow with a very similar fax number.

"This is clearly an error and a regrettable one. The criminal justice unit at Enfield has carried out a review of what happened and has resolved the problem."

It turned out that staff at Edmonton Police Station never needed to send the fax to Harrow Crown Court in the first place, as the police liaison officer can print out files from the police national computer himself.