LaLiga has demanded an investigation into how Paris Saint-Germain have been able to fund a blockbuster new contract for Kylian Mbappe.

The Spanish league body, headed by president Javier Tebas, said it would ask UEFA and authorities in France and at the European Union to investigate the financial affairs of the Ligue 1 champions.

Mbappe's new deal was confirmed on Saturday just before PSG's final Ligue 1 match of the season against Metz

The World Cup winner has signed a deal until 2025, turning down an offer from Real Madrid. It can be reasonably assumed the 23-year-old has penned one of the most lucrative deals in the sport's history.

PSG have been able to attract the likes of Neymar, Lionel Messi and Sergio Ramos away from LaLiga clubs, and Tebas said in a Twitter comment that the French club's president Nasser Al-Khelaifi had become "as dangerous as the Super League".

LaLiga later issued a statement that made savage comments about PSG's business model.

It said a deal such as the agreement with Mbappe "threatens the economic sustainability of European football, putting hundreds of thousands of jobs and sporting integrity at risk in the medium term, not only from European competitions, but also from our domestic leagues".

The statement added: "It is scandalous that a club like PSG, which last season lost more than 220million euros, after having accumulated losses of 700million euros in recent seasons ... with a cost of sports staff of around 650million for this 21-22 season, can reach an agreement of these characteristics while those clubs that could accept the arrival of the player without seeing their wage bill compromised, are left without being able to sign him.

"For all of the above, LaLiga is going to file a complaint against PSG before UEFA, the administrative and tax authorities in France and before the competent bodies of the European Union, to continue defending the economic ecosystem of European football and its sustainability."

PSG have previously denied breaching financial fair play rules.

LaLiga's statement also directly attacked Al-Khelaifi, saying it hoped that "he would refrain from carrying out these practices knowing the serious damage they cause", given he holds down senior administrative roles in European football.

"This type of behaviour led by Nasser Al-Khelaifi... is a danger to European football at the same level as the Super League," the Spanish league's statement said.

It added that PSG's spending "undoubtedly implies non-compliance with the current economic control regulations not only of UEFA, but of French football itself".

Al-Khelaifi has been president at PSG since October 2011, with Qatar Sports Investments orchestrating dramatic change at the French club, bringing a host of global superstars to the Parc des Princes.

Manchester City, under Abu Dhabi-led ownership, are another club who have spent heavily and achieved a level of success in recent years that had been unprecedented in their history. Newcastle United, meanwhile, are now majority owned by Saudi Arabia's Public Investment Fund.

LaLiga said of PSG's spending: "These behaviours denote even more that the state clubs do not respect or want to respect the rules of an economic sector as important as football, key to the sustainability of hundreds of thousands of jobs."