A Pakistani national has been arrested by security agencies from the Indira Gandhi International airport in New Delhi for spying on Indian Defence secrets. The Home Secretary Mr. G.K Pillai said the man was arrested for spying for Pakistan government and passing on defence secrets. Further investigations in the case are on. Asked if the arrest had any connection with the on going investigations into the trails of terror suspect David Headley arrested by FBI or his co-accused Tahawwur Hussain Rana, a Canadian of Pakistan origin, Mr. Pillai said it did not have any connection with the probe. Air correspondent says that security agencies have seized incriminating documents and photographs from the Pakistani spy. <br/>