LONDON - Telecoms giant Vodafone gave British police the mobile phone records of 1,700 people working for News UK, the company that publishes several top British newspapers, The Times reported on Tuesday.
The Times, owned by News UK, said staff had been informed of the breach by chief executive Mark Darcey on Tuesday.
It concerned call records of staff at The Times, The Sunday Times and The Sun between 2005 and 2007, the newspaper said.
News UK chief executive Mike Darcey said in a statement in The Times story that he was "personally appalled" at the breach and that Vodafone had apologised.
"The mobile phone records of journalists - and lawyers - contain privileged information and we have made clear to them that we regard this as a very serious issue," Darcey said.
The police request was made under the Regulation of Investigatory Powers Act, a controversial anti-terrorism law which has been accused of enabling excessive surveillance.
The revelation comes ahead of the presentation of a new anti-terrorism bill in the British parliament intended to increase the ability of police to access computer and telephone data of people suspected of extremist links.
Police used the law in two cases to identify journalists' sources through their phone records, The Times said, a use of the law currently under investigation by a watchdog, the Interception of Communications Commissioner's Office.
The breach occurred after investigators of illegal payments to public officials by journalists applied to Vodafone for the call records of one journalist of News UK, the Metropolitan Police Service (MPS) said in a statement.
"An initial review revealed a volume of excess data, covering more than a thousand different numbers had been inadvertently sent by Vodafone," the statement said.
The police service had pledged that the records, received in March 2014, would only be used "for a policing purpose, when in the interests of justice to do so, and where people were already charged and facing criminal proceedings".
In a statement, Vodafone blamed the breach on "human error".
Once discovered "we urged that the MPS should delete all of the erroneously disclosed data," a Vodafone spokesman said.
In addition, the company informed police that the data was corrupted and urged the police not to rely on it for investigations or prosecutions.
News UK, formerly called News International and part of the media empire of magnate Rupert Murdoch, was at the centre of a phone hacking scandal that led to an inquiry into police bribery and ethics and newspaper News of the World, since shut down.
Six journalists of The Sun are currently on trial, accused of buying stories about celebrities and the royal family from members of the army, prison officials and hospital staff. All six deny the charges.