Michaela McAreavey, who died on honeymoon in Mauritius in 2011.
Armagh City, Banbridge and Craigavon Borough Council has been made aware of disturbing social media content allegedly involving a Council employee.
It is believed that a member of staff is allegedly linked to a video of a song relating to the death of Michaela McAreavey.
The video, which has circulated across social media in recent days, has been strongly condemned and two men have already apologised for their involvement.
A statement from ABC council read:
"While we acknowledge that the behaviour undertaken was carried out in a private capacity, beyond the control of the Council, we wish to reassure the public that we are treating this matter with the utmost seriousness, and have launched an internal
"As an equal opportunities employer, such behaviour does not represent the values of our organisation. We serve all members of the community with respect and dignity, and utterly condemn this type of defamatory and sectarian behaviour.
"We would like to express our sincere sympathy to the McAreavey and Harte families at this distressing time.
"An updated statement will be released in due course."