The Metropolitan Police has been accused of illegally accessing the email communications of journalists.

The Independent Police Complaints Commission is investigating the claims which suggest officers may have broken the Computer Misuse Act and the Regulation of Investigatory Powers Act to spy on journalists.

Claims that journalists illegally hacked phone messages and emails prompted one of the biggest investigations in the history of the Met Police between 2011 and 2016.

No journalists were convicted of computer hacking under the Met’s Operation Tuleta probe – three were arrested.

The new allegations against the Met will test whether new Met Commissioner Cressida Dick will test will show the same robustness as predecessor Sir Bernard Hogan-Howe in pursuing such inquiries.

The Guardian reports that a whistleblower has provided Green Party peer Jenny Jones with evidence of police spying activities.

The unnamed source reported on the activities of an undercover Met Police unit and said: “For a number of years the unit had been illegally accessing the email accounts of activists. This has largely been accomplished because of the contact that one of the officers had developed with counterparts in India who in turn were using hackers to obtain email passwords.”

The letter alleged that reporters and photographers, including two un-named individuals working for The Guardian, were targeted.

The Guardian reports that the letter lists ten individiduals, with specific passwords, who had been hacked. Five of them have been contacted and provided passwords which were identical to the letter.

The letter said, The Guardian reports, that the “most sensitive side of the work was monitoring the email accounts of radical journalists who reported on activist protests (as well as sympathetic photographers) including at least two employed by the Guardian newspaper”.

Police requests to access the content of email communications were covered at the time by the Regulation of Investigatory Powers Act (RIPA), which states that they must be signed of by the Home Secretary.

We already know that the Met Police has widely used RIPA to view the telecoms data of journalists (the what, where and when of calls and text messages – but not the content).

Until March 2015, when the law was changed after the Press Gazette Save Our Sources campaign, such requests to view telecoms data could be signed off internally by the police. Since then, any such request made to identify a journalistic source must be approved by a judge.

In February 2016, the Investigatory Powers Tribunal ruled that the Met Police illegally accessed the call records of a Sun reporter as part of its Plebgate leak investigation. There was no compensation awarded and no punishment for the officer concerned.