According to The Sun, the football star and his father Jorge are being investigated for an alleged 3.4 million-pound tax fraud in Spain between 2007 and 2009, and may face up to six years in jail or be ordered to pay fines of up to six times the amount allegedly defrauded if convicted.
The report further said that Messi's father is accused of being the brains behind the operation - one which allegedly used shell companies and tax havens to hide income relating to Messi's image rights.
According to tax expert Jose Maria Mollinedo, if the Argentine pays and admits his involvement, he could obtain a reduction in the minimum punishment and would not have to go to prison.
However, Messi has denied committed any infringement, stating that he and his father have always fulfilled their tax obligations, following the advice of their tax consultants, who, he added, will take care of clarifying this situation.
Barcelona president Sandro Rosell has also defended Messi, saying that the club supports him and his family as they do not have any doubt about his innocence.
Messi, recognised as the best player in the world, is rumoured to earn 250,000 pounds-a-week and 13 million pounds in endorsements, the report added. (ANI )