CPWD — illegal cutting of trees and construction, and encroachment on government property

Address:

New Delhi, Delhi, 110003

We live in a civil services officers' colony in lutyen's delhi, and the new people who have been allotted a house in our neighborhood have been carrying out illegal activities including large amount of construction on government property. They have completely cut some trees from their lawn, and have constructed an entire two-room-one-bath apartment in their backyard.
In addition, they have reconstructed the boundary wall of their house, and now it encroaches on the road which is at a turn, and hence makes it difficult for cars to take a turn.