Mr Knowles, a married man with a stepson, was from Ballintotis just outside Midleton.
Gardai and the Health and Safety Authority are investigating the fatal incident.
The deceased, understood to be in his 40s, died at a whiskey maturation warehouse at Dungourney, around nine kilometres outside the town.
The exact nature of the incident is unclear but it is understood he sustained crush-like injuries and that the tragic incident occurred shortly after 9am.
Gardai confirmed that its officers from Midleton and members of the emergency services attended a scene in Midleton where a man in his 40s was pronounced dead.
Mr Knowles was later removed to Cork University Hospital and a post-mortem was due to be carried out.
The Health and Safety Authority (HSA) confirmed that the incident had occurred on the Irish Distillers site at Dungourney and that it had launched an investigation into the circumstances.
The Dungourney site is used as a satellite maturation site and has been the subject of investment worth more than €100m by the company in recent years. Four years ago locals in the area celebrated the arrival of the first barrels of whiskey to the warehousing facility.
The distillery is a world leader and home to globally recognised brands, including Jameson, which had sales of 5.7 million cases in 2016.
In the aftermath of yesterday’s tragic incident the company issued a brief statement in which it said it was cooperating fully with the two investigations that are now underway.
"Irish Distillers regrets to confirm that one of our members of staff was involved in a serious incident, which resulted in a fatality this morning in Dungourney, Co Cork," it said.
We would like to express our deepest sympathy to his family. We are offering all the support available to those affected by this tragic accident.
"At this time, it would be inappropriate for us to comment further, as the incident is the subject of an investigation by An Gardaí Síochána and the Health & Safety Authority. We are cooperating fully with the investigation."
Irish Distillers employs 600 people nationally, with around 200 of those employed in its different facilities in and around Midleton.