Devon and Cornwall Police have won a legal challenge to a decision ordering them to reveal the location of road cameras in the two counties.

Campaigning journalist Steven Mathieson, editor of Guardian Government Computing, demanded that the sites of automatic number plate recognition (ANPR) cameras be released in 2009 under the Freedom of Information Act.

But the police’s refusal to hand over the data sparked a long-running legal row over the implications of the cameras’ positions being known to the public.

The issue is now set to be reviewed again later this year, after an appeal judge quashed an earlier decision that the information be revealed.

The upper tribunal was told police refused to say where the ANPR cameras were in August 2009, stating reasons of national security and the prevention of crime.

Its reply to Mr Mathieson read: “If the locations of these cameras were published, potential criminals would know where they are and could bypass or avoid them entirely.

“This would mean that the force would be less able to detect and reduce crime on the roads.”

But the force’s refusal to give up the locations was overruled by a first-tier tribunal last year, which ordered police to release the information within 35 days, pending an appeal.

The first-tier tribunal found: “There was, overall, a weak case made by [the Chief Constable of Devon and Cornwall] as to why it thought that disclosure of the information sought was likely to prejudice policing.”

It added: “It does not seem to the tribunal that the argument and evidence before it were sufficient for it to find that the public interest in effective policing outweighed the public interest in disclosure of the requested information.”

The Chief Constable has now won an appeal against that decision, which Judge Charles Turnbull, sitting at the upper tribunal, ruled was “wrong in law”.

Judge Turnbull ordered that the matter be considered afresh by a new first-tier tribunal.

“Factual issues as to... where the balance of the public interest lies are ones to which the composition of a first-tier tribunal is particularly suited,” he said.

“It is in my judgement not necessary or appropriate for me to do anything more than to set the first-tier tribunal’s decision aside and remit Mr Mathieson’s appeal...to be redetermined by an entirely differently constituted first-tier tribunal.”