As a part of the continuing investigation of large scale illegal disposal of waste in the Mobuoy area of Derry, a joint operation was carried out today by Northern Ireland Environment Agency (NIEA) and PSNI.
They were assisted by officers from Serious Organised Crime Agency (SOCA).
A DOE spokesman said: “During the course of the operation two commercial and five residential premises were searched under Proceeds of Crime Act powers. The premises concerned are located in County Derry and County Armagh.
"During the searches documentation was seized for further analysis and a number of items of computer equipment were also removed for examination.
"The operation makes further use of the NIEA/PSNI strategic partnership designed to tackle environmental crime and makes the best use of both organisations resources.
"This operation follows action on 5 June 2013 in which the Waste Management Licence for City Industrial Waste Ltd, Mobuoy Road, Derry was revoked by the Department following the detection of serious illegal waste management activities in the premises and in a number of land folios in the area – known as Operation Sycamore. Two individuals have previously been arrested in the course of the investigation.
"The investigation remains ongoing.”