They said the Department "cannot provide any further detailed comment, as matters are subject to active investigation".
The Department of Agriculture will not reveal where horses are being relocated following the suspension of activity at a plant run by Shannonside Foods in Straffan.
An investigation has been launched into animal welfare at the plant.
Footage emerged recently of horses being severely mistreated.
Citing the ongoing investigation, a spokesperson for the Department of Agriculture said the slaughter plant is subject to legal notice prohibiting the movement of equines into or out of those premises, unless prior approval of the Department is granted.
They said the Department "cannot provide any further detailed comment, as matters are subject to active investigation".
Martina Kenny from Moyvalley-based animal charity My Lovely Horse Rescue said the public needs to know what's happening behind closed doors.
She said there could be similar operations happening all around the country.

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