The Long War Journal, an online forum tracking counter-terrorism operations, reported during the weekend that intercepted radio communications between Taliban fighters led intelligence authorities to suspect Mehsud was killed in an airstrike last Thursday in northwest Pakistan.
Ehsanullah Ehsan, a spokesman for the Pakistani Taliban, was quoted by The Times of India as saying the reports of Mehsud's death weren't accurate.
"There is no truth in reports about his death," he said. Unnamed Taliban commanders said the reports were a ruse to get the Taliban leader to surface.
Pakistani Interior Minister Rehman Malik was quoted by Voice of America as saying Islamabad wouldn't confirm the reports without "DNA evidence."
In October, the U.N. Security Council included Mehsud on its list of individuals subject to an asset freeze, travel bans and arms embargo under Security Council Resolution 1904.
The U.S. State Department announced in September it was offering a $5 million reward for information about the location of Mehsud.
Anonymous U.S. government officials told CNN in February 2011 that Mehsud died from wounds suffered during a Jan. 14 airstrike that year in North Waziristan. Pakistani officials said his body was buried in late January, though both reports proved inaccurate.