Lionel Messi was greeted with abuse upon his arrival at the Eighth Court of Barcelona to testify in a tax case.
Messi and his father, Jorge, have been charged with three counts of tax fraud worth EUR4.1million which date back to a period from 2007 to 2009.
The Barcelona forward's lawyer Enrique Bacigalupo was present when proceedings began on Tuesday, but the 28-year-old arrived to testify personally on Thursday.
Messi was met with a mixed reaction during his walk up the courthouse steps, but one voice from the crowd jeered: "P*** off and play in Panama, b*****d!"
Messi is due to represent Argentina in the first match of their Copa America Centenario campaign against 2015 winners Chile in California on Monday.