They used to catch crooks - now they trawl Twitter. Are our police turning into spies?

Just before the hacking scandal broke, the Sun sent a young and by all accounts decent reporter to meet a woman who said she had a story — a ‘walk-in’ as we call them in the trade.

The walk-in produced a phone and said the Sun would want to take a look. One picture on it showed the face of a much-loved TV presenter. The rest of the celeb’s body was more lustful than lovable, however, as he was exposing his member in triumphant fashion. Accompanying the picture was a lot of explicit sex talk. The phone looked as if it belonged to the star’s mistress, and the very famous and very married presenter had been sending her pornographic ‘selfies’ and sex texts to remind her of the joys that awaited her when they next met.

The reporter took the phone. Contrary to received wisdom, tabloid hacks are not all monsters. He told the Sun’s lawyer he suspected his contact had stolen the phone. He and the lawyers killed the story. He gave the phone back to the walk-in. Later the police arrested and cautioned her under the Theft Act, and returned the phone to its rightful owner.

That seemed to be that. The reporter moved on to another job as a foreign correspondent in the States. The petty thief had only a tiny mark on her criminal record that hardly anyone would know about. The celebrity continued to keep his sex life private.

It was as if nothing had happened, until three years later in 2012 the police arrested the reporter for possession of criminal property and a catch-all offence that could trap every investigative journalist — ‘computer misuse’ — a charge without a public interest defence. He lost his job and his new life in America. Like scores of other journalists and confidential sources — more now than ever before in British history — he is waiting to see if the Crown Prosecution Service will send him to the dock.