Publisher Orion and author Graeme McLagan have won an important victory for press freedom in a libel battle over Bent Coppers, a book alleging police corruption.

The book suggested there were cogent grounds to suspect that the claimant, ex-Metropolitan Police detective constable Michael Charman, colluded in a substantial fraud by a man from whom he and another officer received corrupt payments totalling £50,000.

The publisher and author argued the book was carefully researched and compiled in accordance with the well known 10-point “responsible journalism” check-list laid down in Reynolds v Times Newspapers Ltd. They claimed the book was protected by qualified privilege.

Trial judge Mr Justice Gray disagreed, saying they had failed to show they acted responsibly in communicating the defamatory statements about Charman to the public.

But the Court of Appeal overruled him.

Lord Justice Ward said: “Having given the matter most careful consideration, I am totally satisfied that this was a piece of responsible journalism.”

He considered it was the sort of neutral investigative journalism which Reynolds privilege exists to protect.

The press has welcomed the ruling as a boost for investigative journalism, both for book authors and reporters.

Elsewhere, top barrister Antony White QC this month warned a media law conference that the Data Protection Act could become an “even greater problem” for the media following a recent Court of Appeal ruling about the data processes involved in a risk manager’s decision to withdraw insurance cover from a consultant surgeon, Johnson v Medical Defence Union.

The case raises questions about whether the court had been right to hold, on the basis of scant evidence in supermodel Naomi Campbell’s well known claim against the Daily Mirror, that the print media “process” information for the purposes of the Act when an article is prepared by both manual and computerised work in the newsroom.

In Johnson, two of the three judges held that manual selection of data prior to its automatic processing by computer did not amount to “processing” under the Act. They felt that if it did, it would lead to a very wide range of situations and decision-making procedures becoming justiciable under the Act purely because a computer had subsequently been used.

Antony White said: “It seems to me it may be worth considering, if data protection becomes, as I have been warning for years, an even greater problem for the media, whether to re-visit in a test case with proper evidence the question of whether the print media at least are ‘processing’ when articles are written.”