Harry Potter and the lawyer's brief

The security surrounding the latest Harry Potter novel escalates. Nuclear secrets have never been so well protected. Now lawyers acting for JK Rowling have issued a High Court injunction against somebody whose identity they don't even know.

In the wake of the theft of copies of the fifth, as yet unpublished, Harry Potter book, lawyers have made legal history by securing a court order against an anonymous defendant – dubbed "John Doe". It follows the discovery of two copies of Harry Potter and the Order of the Phoenix in a field near a printing plant in Suffolk. Chapters from the book were also offered to several tabloid newspapers by someone described in The Sun last week as "a shifty-sounding man".

"To our knowledge this is the first time in this country in over 150 years that a defendant is presently unknown", said Keith Schilling, Ms Rowling's solicitor. "It has therefore established an important legal precedent, particularly in the area of intellectual property piracy."

The order is of a kind that one would normally expect to be used to prevent disclosure of nuclear secrets by renegade MI5 agents. It is intended to prevent whoever was responsible for the thefts from making any details public.

Explaining the ruling, which was given at the High Court by Mr Justice Laddie last Wednesday, Mr Schilling said: "The true identity of 'John Doe' has not yet been discovered. It has therefore been necessary to serve this order under the principles established in the Spycatcher case. In the meantime rigorous attempts will be made to locate John Doe."

Though never before invoked in Britain, John Doe orders have long been used in America to enable action to be taken against people whose identities are not known.

News of the court order comes five days after The Sun first reported that it had been handed two copies of the Harry Potter novel found in a field.

A 44-year-old man has since been charged with stealing copies of chapters of the novel. Three others, including two boys aged 16 and a man aged 18, have been charged with handling stolen goods. The new novel will officially be published next month.