The PSNI is facing questions over their handling of a probe into the anonymous Twitter accounts of officers and staff allegedly involved in online abuse and trolling.
An investigation was launched 12 months ago to trace the identity of individuals behind a number of Twitter accounts, which also appeared to publish information about ongoing police operations. The accounts under investigation were disconnected last week.
It is understood that the PSNI is now aware of the identity of the officers allegedly involved.
However, it has emerged that none of the officers have been suspended from duty, despite growing public concern over a number of the posts made from the accounts.
An internal police probe was first launched last year, shortly after the PSNI's Chief Constable received online criticism for comments he made on social media to an officer.
George Hamilton apologised after he told an officer on Twitter in August last year to stop "wallowing in self pity" and "dry your eyes" after he raised concerns about the increasing pressures of the job.
Following the online exchange, a number of anonymous Twitter users, suspected of being police officers and staff, criticised the Chief Constable and posted complaints about the job and PSNI management.
A fake recruitment video was also made and posted on YouTube by one of the Twitter users under investigation.
The video shows a number of PSNI officers dancing beside a police helicopter and at other sites across Northern Ireland.
A voiceover says: "Are you considering a career where every day you drive home you fear you will be shot? Do you want the rush of wondering if the IRA has planted a bomb under your car?
"Do you want to be told to dry your eyes when asking for mental health support? Then join the Police Service of Northern Ireland today. Recruitment is now open to a host of new officers to be belittled by senior management teams, spat on by the public, harassed by the Police Ombudsman and have their spirits crushed."
A security source said it was around this time that attempts were made to trace the suspected owners of a number of Twitter accounts.
The source said the account that began to cause the greatest concern to management was being run under the Twitter handle @DonYeeoo because of alleged racist and sectarian comments, trolling of other social media users and sharing of classified police information.
SDLP MLA Patsy McGlone said he was concerned to hear that nobody has been suspended from duty.
He said: "If officers were behind these and the PSNI knows what has been said and posted, why haven't they been suspended? It doesn't do much for public confidence when it appears that the PSNI is not taking this type of abuse and trolling seriously.
"Not to mention the possibility of interfering with the justice system by publicising details of ongoing police operations."