"As they can expect, Manchester City Football Club and City Football Group have sought legal advice and will act accordingly", the statement continued.
The La Liga president made his accusations public at the Soccerex conference in Manchester on Wednesday - where City chief Ferran Soriano was present - as Tebas said, via BBC Sport: "It's a good thing that a club like Girona has a backing, but obviously there is a closer watch from La Liga to that club".
'Uefa and other institutions - European Union - need to carry out investigations, ' Tebas said.
Jan Kruger GettyImages
"They are laughing at the system".
'They've agreed sponsorships which are not based on market rates, ' he added.
The La Liga boss urged Uefa to crack the whip against two clubs he accused of flaunting their financial power in defiance of FFP rules created to prevent clubs from being bankrolled by external sources and spending beyond their means. Neymar has peed from diving board.More news: NIA raids 10 locations in J&K, NCR
"I have informed the club by email and registered a letter that we don't accept this situation", he is reported as saying by L'Equipe.
"This is when the football clubs have competitive advantage not coming from club itself".
The Ligue 1 club were taken over by Oryx Qatar Sports Investments back in 2011 and have since signed a number of the best players in the world for sizeable fees, including Zlatan Ibrahimovic, Thiago Silva and Edinson Cavani.More news: What time does the American Horror Story season 7 premiere start?
Despite Tebas' request for City to also be investigated, Uefa confirmed on Tuesday that there is now no open investigation into the club's adherence to FFP. If Neymar had gone to Man United, it wouldn't have been as important to take this to the courts.
"Manchester City with all this oil [money] will take all these players and we need to protect ourselves".
Manchester City also spent heavily in the last transfer window, lavishing an estimated £221 million (242 million euros, $288 million) on players although they offloaded several too. "The investigation comes after La Liga formally requested such probes into PSG and Manchester City FC in August". They are not financial doping.More news: Evacuation Orders Remain as Eagle Creek Fire Burns Overnight