The former Atletico Madrid forward made a big-money switch to the Stade Louis II in May for a fee reported to be in the region of £50million, with the newly-promoted Ligue 1 outfit officially signing a player registered with FIFA as 27 years old.
However, reports have emerged alleging that he is actually 29, with media outlets in his native Colombia claiming he was actually born in 1984.
Falcao has now hit back at those suggestions, writing on his Twitter account: "I have been surprised with a totally ridiculous news in the media about my age..I want to deny categorically and end this issue once and for all."
The reports come as yet another distraction for the striker, who suffered an inauspicious start to his Monaco career.
He was booked for a string of rash challenges in the friendly against Augsburg, before apparently kicking the ball into the crowd in fury. Manager Claudio Ranieri then substituted him at half-time.
