"If the Police arrive to lock you up, say nothing. You are a decent person and you may think that reasoning with the Police will help. Wrong.” It is not quite the advice you would expect to receive from a serving police officer.

But Detective Constable Richard Horton, of Lancashire Constabulary, gave readers of his NightJack blog the full benefit of the knowledge that he had gained from 17 years in the force as to how to extract oneself from the grasp of the long arm of the law.

“All you are doing by trying to explain is digging yourself further in. We call that stuff a significant statement and we love it.” Other pearls of wisdom included: “Never explain to the police . . . Complain about every officer and everything they do . . . [and] show no respect to the legal system or anybody working in it.”

Mr Horton, 45, who joined the police after a career as an accountant, attracted nearly 500,000 readers each week to his blog at the height of its appeal, drawn in by its pithy observations of life on the front line of policing.

He began the blog in February 2008. Critical acclaim followed, with a prestigious Orwell Prize for political writing, in April this year. At that stage he stopped, swapping virtual pages for their paper counterparts after using the attention to land the services of a top book agent.

What the Orwell Prize judges did not know is that he was also using the blog to disclose detailed information about cases he had investigated, which could be traced back to real-life prosecutions.

Each involved sex offences, often committed against children, and could be linked to investigations in the Lancashire area. One entry described the author investigating the rape of “Melissa”, a 14-year-old girl who was plied with alcohol and then raped in a hotel room.

Mr Horton wrote that the offender had an Asian name, had hepatitis and assaulted the girl at a seaside hotel. He concluded: “Now me, if I had video of me molesting a 14-year-old on my phone, if I had used a well positioned door mirror to video my grinning evil self on the job and I was charged with raping her, I would delete it.”

A month earlier Ajmal Mohammad received an indefinite sentence at Preston Crown Court for raping a drunk teenager in a Blackpool hotel room. The court heard that he was infected with hepatitis C and had filmed the attack on his mobile phone.

On the blog, Mr Horton revealed information that could have influenced the case, such as his suspicions that a key witness had misled police. Other cases described on the blog that can be traced to real events include the rape of a woman by a taxi driver and a child pornography investigation.

Mr Horton was adamant that he had taken great pains to keep his identity secret. But on his blog, he also described his visits to a jiu-jitsu club, adding a hyperlink to the website of the organising body for the martial art. Lancashire Constabulary jiu-jitsu club lists only one member who is a detective — Detective Constable Richard Horton.

Mr Horton was also a member of a number of social networking websites. Those who logged on to his account on the Facebook website could follow posts written by his brother, Roger, who currently lives in Texas. The pair had conducted a conversation about the blog on a publicly accessible part of the website.

Mr Horton has deleted the blog and received a written warning for misconduct from his police force. His superiors are now aware of further allegations that he was also using the blog to disclose information gained during his investigations.