FC Barcelona have been hit with a huge €15.7 million ($17.1 million) fine from the Spanish tax office for making "irregular" payments such as those that allegedly went to former players, according to El Confidencial.

Cash-strapped Barca are already facing economic difficulties. Mired in debts, the Catalans are being forced to shave €200 million ($220 million) from the wage bill just to sign new players and register the renewed contracts of existing stars.

Currently in the courts after a charge for "continued corruption" related to payments to the former Vice President of the Referees Committee, Barca have fresh legal and financial headaches El Confidencial reports.

This is because an investigation by the Tax Agency, known as the Hacienda, has led the authority to conclude that Barca should be hit with a fine exceeding $17 million for alleged "irregularities".

According to information obtained by the Spanish newspaper, these alleged irregularities pertain to transfering Audi cars to members of staff, not declaring the payment of charter flights for players and incorrectly filing payments received by former players Arda Turn and Alex Song after they left the club.

While the amount attached to Turan is €1.312,500 euros ($1434 million), Song's is a much higher €3.5 million ($3.8 million).

The investigation was launched in 2019 but investigates a period starting from 2015 and could spell further financial problems for Barca.

The football first team is currently on the cusp of its first La Liga title in four years, but badly needs reinforcements to retain the Spanish top flight crown and also compete in Europe after exiting the Champions League in the group stage for the past two seasons.

With Sergio Busquets announcing his departure at the end of the season this week, defensive midfield is one area of the pitch that needs to be shored up while there are also shortages of options at right back and on the wings.

If Barca need to hand over $17 million to the tax office, this could affect planning for 2023/2024 when manager Xavi Hernandez might be able to count on Lionel Messi if he doesn't accept a rumored mega-offer from Al-Hilal in Saudi Arabia.

As Barca needs to present a viability plan to La Liga to show they can pull off the Messi coup when he becomes a free agent at Paris Saint Germain on June 30, however, the fine, if true, will not help them in their quest.