Robin Ackroyd, a freelance journalist who wrote an article about the treatment in hospital of Moors Murderer Ian Brady, won his right to protect his source after a six-year legal battle with the Mersey Care NHS Trust. His case was backed throughout by the NUJ and the union’s lawyers Thompsons.

Mr Justice Tugendhat said that Robin was a “responsible journalist whose purpose was to act in the public interest”. He confirmed that there is “a vital public interest” in the protection of a journalist’s sources.

Robin Ackroyd gave extracts from Brady’s medical records to the Daily Mirror, which printed them in an article in December 1999.

The House of Lords ordered the Daily Mirror to disclose the source of the leaked medical records. When Robin came forward, the Ashworth secure hospital launched legal proceedings against him to reveal his source.

Today’s High Court ruling confirms that someone trying to get a journalist to reveal their source must prove a “pressing social need” for the source to be disclosed. After the Human Rights Act that includes a rigorous analysis of all the circumstances of the case. The court said that one of these is the public interest in protecting a journalist’s sources.

“[The defendant] has a record of investigative journalism which has been authoritatively recognised, so that it would not be in the public interest that his sources should be discouraged from speaking to him where it is appropriate that they do so.”

NUJ General Secretary Jeremy Dear said: “This is a fantastic result for Robin and for all journalists. The fundamental point of principle – that there is a strong public interest in upholding journalists’ right not to reveal their sources – has been maintained.

“Robin has showed huge courage in standing true to this principle during six very difficult years. We all owe him an immense debt of gratitude – all journalists are in a stronger and safer position because of the brave stand he has taken.

“The NUJ supported Robin every step of the way and, thanks to the excellent work of our solicitors Thompsons, we have won the day. Justice has finally been done.”

A summary of the High Court decision is available.