The Argentine's foundation is now under investigation by Spanish IRS authorities, who claim that the entity failed to pay up to 10 million euros.

Just when Lionel Messi's tax fraud case had been settled, a new investigation by Spanish tax authorities looms over the Argentine superstar.

After agreeing to pay a fine to have his 21-month sentence expunged by Spanish IRS authorities, a new investigation has begun to clarify the dealings of the Lionel Messi foundation.

A report by Spanish newspaper ABC reveals that Messi's foundation failed to declare millions of euros coming from sponsorship deals from 2007 to 2015.

The foundation's lack of proper tax returns makes it impossible to know where or how that money was spent, according to the Spanish newspape.

The newspaper created a timeline for the foundation, claiming that it began dealings in 2007. Allegedly, the player and his father Jorge, created a sub-office for the foundation in Rosario, Argentina. The NGO hadn't been registered with Spanish authorities until 2013, six years after its creation. Argentinean tax authorities demanded the sub-office to be shut down due to the entity's lack of registration in Spain, where it was supposed to have started its dealings in 2007.

"The Leo Messi Foundation has created a framework to hide millions of euros of income generated from sponsors that has not been declared and, as such, it can’t be confirmed that it has been spent on social projects to help children with problems," can be read in the journal's investigation.

The player, who celebrated his 30th birthday last Saturday, will celebrate his wedding to Antonella Roccuzzo next weekend.