Real Madrid knocked Manchester City out of the Champions League semi-final in May, around the time of La Liga's complaints
La Liga president Javier Tebas has repeatedly attacked the pair, who he describes as 'state clubs', and strongly criticised PSG over the new multi-million pound contract the French club gave star striker Kylian Mbappe in May.
Since then, Premier League City have confirmed the £51.2m signing of Erling Haaland from Borussia Dortmund.
Real Madrid were interested in signing both players.
"La Liga understands that the irregular financing of these clubs is carried out, either through direct money injections or through sponsorship and other contracts that do not correspond to market conditions or make economic sense," said La Liga.
"La Liga considers that these practices alter the ecosystem and the sustainability of football, harm all European clubs and leagues, and only serve to artificially inflate the market, with money not generated in football itself."
The complaint against PSG was made last week and the one against City in April, although La Liga says it reserves the right to extend these complaints.
Both City and PSG have vigorously defended themselves against Tebas' complaints in the past.
In July 2020, the Court of Arbitration for Sport overturned a two-year Champions League ban imposed on City by Uefa for Financial Fair Play breaches.
In April, Uefa approved new financial regulations that included a doubling of the sums clubs could lose over a three-year period from 30m to 60m euros, with some clubs allowed an additional 10m euros if they are in 'good financial health'.
Last month Tebas said La Liga would take legal action against PSG after Mbappe snubbed a move to Real Madrid.
The France international instead renewed his contract with PSG until 2025, and Tebas and La Liga said the contract extension "attacks the economic stability" of European football.
Tebas is due to speak about the issue in depth at a European Leagues meeting in Amsterdam on Thursday.
-- Courtesy of BBC Sport