LONDON, Dec 17 (Reuters) - London police breached the human rights of tabloid journalists by accessing their phone records to find the source for a 2012 story that brought down a senior minister, a tribunal ruled on Thursday.
But the Investigatory Powers Tribunal (IPT) also said the police's use of the covert power had been justified and that the law at the time had been at fault.
Detectives had accessed the data of three reporters from Rupert Murdoch's Sun tabloid, Britain's top-selling newspaper, to find out who had leaked a police report revealing that former minister Andrew Mitchell had insulted officers on duty outside Prime Minister David Cameron's Downing Street office.
The reporters' lawyer, who said it was the first case of its kind, had argued the police actions violated journalists' fundamental rights to protect confidential sources.
The IPT, a body which examines complaints from the public about unlawful use of covert techniques by public authorities, concluded the current surveillance law failed to do enough to protect confidential sources, and thus the journalists' rights had been infringed.
But it also ruled that the police had acted lawfully in three of the four occasions when the covert power was used against the reporters.
"We are compelled to hold that the legal regime in place at the relevant time did not adequately safeguard the important public interest in the right of a journalist to protect the identity of his source," the IPT said.
"The Metropolitan Police cannot be criticised for its decision to use the power ... in aid of the investigation into a serious criminal offence affecting public confidence in the police," it added.
The Sun had reported that Mitchell, who was responsible for keeping discipline among lawmakers in Cameron's Conservative Party, had referred to police as "plebs" after they refused to allow him to cycle his bike through the main gates of Downing Street.
Mitchell denied using that insulting term but in the ensuing row was forced to resign. He later lost a libel case against the paper and the police officer involved in the confrontation.
Four other officers, who had not been present at the time but were responsible for the leak or fabricating evidence about the incident, were sacked with one being jailed.
During the police investigation, detectives applied four times to access phone records of the three Sun journalists involved in the story. One of these authorisations was "not necessary nor proportionate", the IPT said.
A Sun spokesman welcomed the ruling and said the law needed to be changed to ensure journalists' sources were protected.
Since February this year, police must now obtain permission from a judge in order to identify journalists' sources, and this measure is due to be strengthened under government plans for wider surveillance powers. (Editing by Stephen Addison)