The fact that the Syrian government is not allowing an extensive investigation of Imad Mughniyeh's assassination proves that Syria was involved in the killing, the arch-terrorist's widow said Monday. "The Syrian traitors are responsible for his death," she said in an interview in Iran. "Damascus's refusal to let the Iranians investigate the incident is only one more proof of that." Army Radio reported that in the months leading up to the assassination there were rumors of bad blood between Mughniyeh and Hizbullah chief Sheikh Hassan Nasrallah. Mughniyeh, according to the rumors, was trying to usurp Nasrallah and take over as the leader of Hizbullah. Immediately after the assassination, Syria declared that it was leading an investigation and even went so far as to arrest a number of suspects. Damascus, however, refused to allow the Iranians to participate in the probe. Mughniyeh was widely considered to have been the liaison between Hizbullah and Iran.