The Independent reports today that it is holding evidence that a senior individual at Mirror Group Newspapers regularly paid a private investigator for mobile phone numbers and private pin access codes “at least two years before phone-hacking became a routine practice at the News of the World”.

The paper claims that it has been shown invoices naming the individual – who was not identified by the paper – regularly paying up to £125 a time for the information.

The news comes after it emerged yesterday that four people are taking action against publisher Trinity Mirror over alleged phone hacking, it has emerged.