The winger moved to Liverpool in January for an initial fee of £37m from Portuguese giants Porto, signing a five-and-a-half-year contract at Anfield.
Diaz has impressed in Liverpool colours since joining, earning plaudits for settling in at Anfield in quick-fire time and helping to push his side’s quadruple bid.
Liverpool are Diaz’s second club in Europe, with Porto having bought him to the continent from Colombian side Atletico Junior.
And according to Portuguese outlet Maisefutbol, the South Americans have complained to FIFA that Porto are yet to pay them the first payment from their share of the fee from his move to Liverpool.
The Barranquilla outfit are entitled to receive a figure in the €9m range from Porto, as they secured a sell-on clause in his deal when they let him join Porto in the summer of 2019
It is claimed that FIFA have notified Porto that they will have 45 days to pay the money they owe to Atletico Junior.
Diaz’s transfer fee could rise to a whopping £49m if certain add-on stipulations in his contract are met during his time at Anfield.
