The paper said that operational planning for Mughniyeh's Feb. 2008 assassination started with the arrest of Ali Moussa Daqdouq, a Hizbullah 'foreign operations' official, near Karbala, Iraq, in January the same year.
Iraqi security forces later handed over Daqdouq to U.S. intelligence agents who also questioned him regarding Mughniyeh.
The man has reportedly provided the CIA with many details about Mughniyeh, including his phone numbers.
The Americans, according to Yediot, provided the Israeli Mossad with all the information unveiled by Daqdouq.
The paper said that Mughniyeh was assassinated because he committed one big mistake.
The mistake was that several people knew that he would visit Iran's new ambassador to Damascus, on the occasion of the 29th anniversary of the Islamic revolution on Feb. 12.
The paper added that the Israeli assassination team sneaked into Syria from Iraqi-Kurdistan in three vehicles and monitored Mughniyeh's move a day before his assassination, including wiretapping his phone line.
According to Yediot Aharonot, the Israeli team reached Mughniyeh's Mitsubishi Pajero and exchanged the headrest with another loaded with explosives. The Israeli team did not use a time bomb because it feared unforeseen changes.
Once Mughniyeh was seen seated next to the driver's seat, the headrest blew up by remote control, the paper said.
Yediot Aharonot added that Israel fears Hizbullah and its backer Iran would avenge Mughniyeh's killing on the first anniversary of his assassination.