UEFA have opened a Financial Fair Play investigation into Paris Saint-Germain. The French club have had an extravagant transfer window, sewing up a deal for Kylian Mbappe and breaking the transfer record for Neymar.
Friday's announcement from European football's governing body said it would look at whether PSG had violated the regulations, which are designed to prevent football clubs spending more than they earn.
"The investigation will focus on compliance of the club with the break-even requirement, particularly in light of its recent transfer activity," a statement from UEFA read.
Punishments for breaches of FFP range from warnings and fines through to points deductions or banishment from UEFA competitions. PSG are in this season's Champions League.
"The club is surprised by such a decision since it constantly kept UEFA's financial Fair Play teams informed of the impact of all the player transfers carried out this summer despite not being obliged to do so," PSG said in a statement.
The French club have been among Europe's biggest spenders since a Qatari takeover in 2011. They have fallen foul of the regulations before and were fined €60 million (€40 million of which was suspended) in 2014. They were only freed from the associated restrictions in April.
Last year's Ligue 1 runners up signed Brazilian striker Neymar from Barcelona for a world-record €222 million ($264 million) on August 3 and completed a loan move for Kylian Mbappe on Thursday in a deal that includes an option to buy the French teenager for 180 million euros.