The company handling post for Irish Water has confirmed that it received an item containing "offensive matter" in recent days.
Abtran has confirmed that one of its offices in Cork received the item of post in recent days.
The item in question is believed to have been a returned information pack that had been smeared in excrement.
Abtran say the matter is being viewed as an isolated incident and confirmed that all necessary security protocols are in place for mails received including provisions for the health, safety and welfare of staff on an ongoing basis
Gardai have been asked to investigate.
A statement from Abtran stated: "No members of staff were impacted directly by this occurrence other than it being an offensive matter."