PC Nick Manning is accused of encouraging burglars after he used Twitter to disclose that a large part of the county he covered was being manned by just three officers at night.
He also used the social networking site to criticise Home Secretary Theresa May for slashing police jobs and to make sarcastic comments about his senior officers.
In one tweet, PC Manning wrote how he wasted three hours by taking a ‘crook’ home, adding: “Didn’t realise we really are a taxi service.”
The officer has now revealed on Twitter that he has been issued with a “regulation 14” notice by superiors, meaning he is under investigation for possible misconduct.
He stated that he is accused of undermining public confidence and bringing discredit on the service.
PC Manning, who serves with Dorset Police, told his 192 followers: “Might be taking a break from tweeting as I’ve just been reg 14’d for ‘inappropriate content’ on here. Should be an interesting interview.”
He added: “Thank you all for your support, my reg 14 says I undermine public confidence and bring discredit on the service… we’ll see how it goes.”
Nick King, a member of the Dorset police authority, said: “It’s not unusual for an officer to tweet how they feel about police cuts – I follow quite a few officers who do that.
“As an individual, he has got every right to say what he likes. But if you are in a public position there’s a line to be drawn.
“And if he is saying there are three police on duty in the north of the county, there’s a concern criminals could see that and exploit it.”
PC Manning, who is based at Blandford police station, began his Twitter feed a year ago.
He described on his profile that he was a ‘busy cop’ in Dorset and carried a disclaimer that his views were his own and not the force’s. He added: “Never be scared of the truth or free speech.”
He has used Twitter to highlight problems facing rank and file officers and to protest against government cuts.
He ended many of his tweets with the hashtag – an easy way to identify a Twitter subject matter – of ‘£noconfidenceintheresamay.’
In September 2011, he wrote: “Police wasting money on backroom posts? How about halving the amount of C. Insps and above? Trust me the frontline will probably benefit.”
On October 14, he wrote: “Dorset is already suffering with cuts, key staff gone and cops stuck in nicks doing their work and no wonder there’s £noconfidenceintheresamay.”
On the same day, he revealed there were just three police officers in the large area of North Dorset.
He wrote: “Last 3 nights in North Dorset, 3 cops covering everything north of the A31. The public should have £noconfidenceintheresamay.”
PC Manning also criticised the negative aspects of policing.
On June 21 last year he posted: “3 hours wasted last night taking a crook home from Poole custody. Seem we really ARE a taxi surface for ‘risk averse’ custody skippers.”
PC Manning is a Dorset Police Federation representative, chairman of the constables board and acts as a ‘discipline friend’ for officers who are themselves accused of misconduct.
Steve Davenport, of the Dorset Police Federation, said: “As the matter is under investigation we are unable to make a specific comment at this time.
“However Dorset Police Federation is aware that many Dorset Police officers enjoy using social network sites whilst off duty.
“All police officers have a right to a private life and as such should be entitled to make responsible use of any social networking site.”
Bob Walter, the Conservative MP for North Dorset, said: “I have every confidence that the chief constable will deal with it as a disciplinary matter.
“Obviously policeman should not be expressing party politics views in their capacity as police officers.”