Western intelligence agencies warned former Lebanese prime minister Saad al-Hariri of an assassination plot against him, the Saudi-owned pan-Arab newspaper Asharq al-Awsat reported on Sunday.
It cited unnamed sources close to Hariri.
However, al-Mayadin, a Lebanese news channel, reported that Major General Abbas Ibrahim, head of Lebanon's General Security, told it that he was not aware of any information about an assassination plot against political figures in Lebanon.
Asharq al-Awsat reported that the sources "revealed that he had received Western warnings of an assassination attempt that was prepared against him". It did not give further details of the alleged plot.
Hariri announced his surprise resignation on Saturday, citing a plot to kill him, and saying the climate in Lebanon resembled that before the assassination of his father Rafik al-Hariri, who was also prime minister, in 2005.
He criticised Iran and its Lebanese ally Hezbollah for their role in Lebanon and other Arab countries.
Hariri travelled to Riyadh on Friday and did not return to Lebanon. His resignation was made in a televised statement from an undisclosed location. Saudi Arabia is an arch rival of Iran.
Asharq al-Awsat reported the same unnamed sources as speculating that Hariri would probably remain outside Lebanon because of the security threat against him.
On Saturday, Saudi-owned television channel al-Arabiya al-Hadath, part of the same media group as Asharq al-Awsat, reported that an assassination plot against Hariri had been foiled in Beirut days earlier, citing an unnamed source.
Saudi Gulf Affairs Minister Thamer al-Sabhan said in a television interview that Hariri's personal security detail had "confirmed information" of a plot to kill him.
Lebanon's internal security force said in a statement on the reports that it had no information about the matter.