A secret report into a botched murder investigation is set to be made public after a regional daily’s year-long Freedom of Information campaign.

The Information Commissioner has ruled Staffordshire Police must make public a report into its handling of the inquiry into the death of Kevin Nunes, left.

The force had twice rejected requests by Wolverhampton daily the Express & Star for a copy of the document, known as the Costello Report, but will issue a redacted version next week after the case was referred to the ICO.

Mr Nunes, 20, was pistol-whipped and shot five times in a country lane in 2002 as part of a drugs turf war.

In 2008 five Black Country gangsters – Adam Joof, of Willenhall, Levi Walker, of Birmingham, Antonio Christie, of Great Bridge, and Owen Crooks and Michael Osbourne, both of Wolverhampton – were given life sentences after being found guilty of the amateur footballer’s murder at Leicester Crown Court.

But their convictions were quashed after it was revealed details of police failings had never been disclosed at the original murder trial.

In November, the Express & Star published a series of new details about the way the murder probe was compromised following its own three-year investigation.

It revealed that a detective responsible for handling the key witness conducted an affair with a female colleague at a safe house which could have led to evidence contamination, while the witness was also ‘chaotic’ while in force protection and caused thousands of pounds of damage to a taxpayer-funded safe house and stole hundreds of pounds of police funds.

E&S editor Keith Harrison told HTFP: “Our success in getting the Costello Report released by Staffordshire Police to the public shows the importance of investigative and public interest journalism in holding police forces to account and campaigning for transparency.

“It has to be said that we have yet to see the full report, so we must reserve some level of judgement at this stage. But great credit must go to Rob Golledge, our Investigations Editor, for his dogged determination to get to the bottom of the failings that led to this botched murder case.

“The FoI battle has taken 12 months, but overall this has been an in-depth three-year editorial operation working with whistleblowers, contacts, and those close to the murder victim.

“While we are hugely supportive of our local police forces, we are determined to hold them up to public scrutiny – particularly when some of the country’s most senior officers are involved.”

The Express & Star has also been campaigning for the Independent Police Complaints Commission’s investigator’s report into the investigation, known as Operation Kalmia, to be made public.

It remains unpublished despite being completed two years ago.

Former detective Joe Anderson, who turned whistleblower and reported concerns over the way the murder probe was handled, said: “I welcome the news that Staffordshire Police and the IPCC have signalled that they are now prepared to release a redacted copy of the Costello Report and Operation Kalmia final report, however I fear that the ‘redaction’ process may be abused to conceal embarrassing facts.

“Time will tell whether the move is a genuine movement towards openness and transparency or a deliberate and cynical continuation of the whitewash.”