A Belfast river ran red yesterday after up to 30 litres of red ink accidentally spilled into it.
Packaging firm Delta Packaging said it is responsible for the pollution spill in the Blackstaff river which was reported to the Department of Environment (DoE) yesterday.
Director at Delta Packaging, Neal McCone, told the BBC "human error" caused the spill.
"It is an accidental discharge of one of our inks which is a water-based, food-safe ink so it poses no threat to the environment," he said.
Mr McCone said between 20 and 30 litres of the dye were spilt.
"It doesn't paint a very attractive picture but even now, it has been significantly diluted at this stage," he said.
The DoE and the Northern Ireland Environment Agency are investigating.