We propose a thought experiment for classical superluminal signal transmission based on the quantum nonlocal influence of photons on their momentum entangled EPR twins. The signal sender measures either position or momentum of particles in a pure ensemble of the entangled pairs, leaving their twins as localized particles or plane waves. The signal receiver distinguishes these outcomes interferometrically using a double slit interferometer modified by a system of optical filters. Since the collapse of the wavefunction is postulated to be instantaneous, this signal can be transmitted superluminally. We show that the method circumvents the no-signalling theorem because the receiver is able to modify the disentangled wavefunction before his measurement. We propose a plan for the possible practical realization of a superluminal quantum telegraph based on the thought experiment.