La Liga has urged UEFA to take action against Manchester City and Paris Saint-Germain after leaked documents showed the clubs had allegedly breached financial fair play (FFP) regulations.
On Friday, German magazine Der Spiegel released a number of stories, based on so-called Football Leaks data, alleging that City and PSG had bent rules to avoid FFP sanctions and the threat of being excluded from European competition.
In a statement to ESPN FC, La Liga said: "The Football Leaks documents appear to confirm what we have been saying for years -- PSG and Manchester City are violating financial fair play rules and should be sanctioned. That continues to be our position.
"We certainly hope UEFA will take the right decisions and enforce financial fair play rules. Should UEFA fail to act, we will do what we have said before -- launch a complaint with EU competition authorities."
UEFA told ESPN FC it was unable to comment because of confidentiality obligations.
Oryx Qatar Sports Investments, which owns PSG, is alleged to have injected €1.8 billion since 2011 with help from former UEFA president Michel Platini and current FIFA president Gianni Infantino.
City's owners, the City Football Group, are said to have injected €2.7bn over the past seven years through shareholders and over-valued sponsorship contracts exceeding FFP limits.
Last year, La Liga president Javier Tebas accused PSG of "cheating economically" and called on UEFA to expel them from the Champions League if they were found to have broken FFP rules.
UEFA opened an investigation that resulted in PSG and City being fined and facing transfer and squad restrictions.
On Monday, PSG filed an appeal case with the Court of Arbitration for Sport against UEFA's decision to reopen an FFP investigation into them.
Financial fair play was approved in 2010, with the first assessments beginning a year later and the first sanctions imposed in May 2014.