Waste from three centres in Cahir, Clonmel and Kilkenny, operated by the national heritage service was deposited at an illegal site in south Tipperary regularly over the last three years.
On Friday, another load of waste from a Dúchas site was tipped at the unlicensed landfill located 3 km from the village of Killenaule, Co Tipperary, at Burnchurch, Moyglass.
Waste manager with South Tipperary Co Council, Mr Jimmy Harney, confirmed that a truck dumped the rubbish at the site before lunch. This was on the same day that the illegal activity at the site was highlighted in The Irish Times.
The truck driver unlocked the gate and drove the lorry into the former sand pit which is hidden from the public road.
Mr Harney also confirmed that the county council is investigating claims by Deputy John McGuinness that large amounts of asbestos were deposited at the site.
On Wednesday, inspectors from the local authority bored 40 test holes and took away a large amount of samples for analysis.
Mr Harney noted that Dúchas were co-operating fully with the investigation as was the landowner. He added that prosecutions would follow against the parties involved.
Deputy John McGuinness, the Carlow/Kilkenny TD, said the Minister for the Environment, Mr Cullen, should not attempt to blame the tradesmen and general operatives in Dúchas for what had happened.
He made the comment after a lorry from the Dúchas depot in Kilkenny city was filmed dumping material at the landfill last week.
"Illegal dumping over many years is a management problem.
"Where did they think the rubbish was going," he asked.
He also claimed that the number of bullying and harassment cases within Dúchas was frightening.
"It does not surprise me that the organisation has refused to answer my parliamentary question asking for the total number of bullying and harassment cases nationally.
The material deposited at the site outside Killenaule includes storage heaters, lagging, plastic bags, a number of large bags of concentrated lime, chairs, rubber, paper, cardboard and Dúchas brochures.
It also includes refuse including milk cartons, plastic bottles, and food waste, plastic piping, bags of cement, plastic buckets, large metal barrels, plastic covering for silage and copies of the Heritage Week 2000. A spokesman for the Department of the Environment said an internal investigation was underway.