An internal garda investigation is underway into alleged grievances surrounding the process of garda promotion.
The probe began after an anonymous letter was sent to a large number of Dublin garda stations.
The letter, allegedly sent by a garda who is attached to Dublin's "south central division", claimed that a number of officers were promoted after they attended a social event organised by an officer who is part of the force's national management team.
Sources said that the letter had been faxed and also placed under doors of offices in some stations.
The Herald is aware that there has been increasing anger among a large number of gardai about the recruitment process that took place within the force earlier this year.
However, it has also been established that the allegations that certain gardai were promoted after attending a social event are untrue.
In fact, senior sources say that the named officer has been a "unifying force" within the gardai and is expected to apply for the role of Garda Commissioner after decades of respected service within the organisation.
It is understood that acting Garda Commissioner Noirin O' Sullivan is aware of the contents of the letter which has been obtained by the Herald.
Since the letter, dated September 4, was circulated to officers, an internal investigation has begun.
However, sources in garda headquarters say that there is no "witch hunt" in relation to the matter.
A source said: "The Commissioner is more interested in hearing what this member's issues are with the process rather than going after any individual.
"She wants to find out if there is evidence to support these claims and if there is, she wants to see if there is anything she can do about changing things.
"If this member has issues, there are forums within the organisation that the person can use to address such matters."
The letter also outlines major concerns that many gardai feel about the Garda Siochana Ombudsman (GSOC) and how they investigate complaints against gardai and it criticises the Garda Representative Association.