Vodafone inadvertenly divulged phone data of more than 1,700 News UK staff to the Metropolitan Police Service last year, after coppers requested the details of just one journalist in relation to payment of public officials for information.

The Met then analysed the data of all outgoing calls made from the phone numbers they had been given, waiting several months before telling the phone company a mistake had been made.

A spokesman for Vodafone told the Times, owned by News UK, that: "We wrote to the Met to express our grave concern that the police continued to retain the data released to them in error and made it clear to them that any assumption that meaningful conclusions could be drawn from any aspect of the corrupted dataset was highly questionable."

In addition to disclosing the phone data of more people than had been requested, the phone operator also released data from a greater time-span than had been requested.

After being informed of the incident, the Interception of Communications Commissioner’s Office (IOCCO) demanded a full explanation of what had been leaked, as well as details of what measures had been put in place to prevent a repetition of the incident.

The office also told the Met that it was obliged to retain any information that comes into its possession that has relevance to a criminal investigation, but that it is also required to disclose information to a defendant if it is to their advantage.

The case has also been referred to the Information Commissioner’s Office (ICO), which has yet to release a statement on the matter.