Modric's wife, Vanja, is also being accused of tax irregularities.

Prosecutors said Wednesday they were informed last month that Modric may have "financial positions" in the Isle of Man, and they were not known by tax authorities and could have affected the amount of taxes the player was supposed to pay in Spain.

The Croatia midfielder has been playing for Madrid since being signed from Tottenham in 2012.

The accusations against Modric came a day after Madrid left-back Marcelo appeared in a Madrid court in another tax case. The Brazil international is being accused of defrauding authorities of €490,917.70 ($585,375) by using companies abroad to handle his earnings from image rights.

Other players have been targeted by Spanish authorities recently, as well.

Last year, Lionel Messi and his father were found guilty on three counts of defrauding tax authorities of €4.1 million euros ($4.8m) from income made from image rights.

Cristiano Ronaldo, Ricardo Carvalho, Angel Di Maria, Javier Mascherano, Radamel Falcao and Fabio Coentrao are among other players investigated by Spanish authorities.

Former Real Madrid coach Jose Mourinho, currently at Manchester United, also is being investigated.