UEFA warned Monday that clubs whose finances have already been scrutinised by its Financial Fair Play regulations may not be out the clear yet, European football's ruling body told AFP.
Less than a week after the latest revelations in the Football Leaks series, UEFA suggested it could reopen previously concluded cases should new information arise.
Every club affiliated to UEFA faces an annual assessment against the break-even requirements and many have been investigated and either sanctioned or cleared.
But it now seems UEFA may go back over some closed cases.
"Should new information suggest that previously-concluded cases have been abused, those cases may be capable of being re-opened as determined on a case by case basis," UEFA told AFP.
"FFP relies on the cooperation of clubs to declare a complete and genuine financial position," UEFA said.
"It relies on that information being fair and accurate."
The announcement comes after the whistle-blowing website Football Leaks claimed that between them Qatar and Abu Dhabi have injected some 4.5 billion euros ($5.1 billion) into Paris Saint-Germain and Manchester City respectively over the last seven years.
UEFA allows for only a 30 million euros deficit and insists "Financial Fair Play has led to a steep change in the health of the finances in European club football".
"Seven years ago, European clubs had a cumulative debt of EUR 1.7 billion. Last year it was a profit of EUR 600 million," UEFA said in their statement on Monday.
Football Leaks, however, has pointed the finger at overvalued deals allowing clubs to inject huge sums of cash that are totally imbalanced.
Both PSG and City were fined 60 million euros by UEFA in May 2014, but both were told they would get 40 million euros back if they stuck to the terms of their settlement.
French investigative website Mediapart claims Gianni Infantino -- the current FIFA president who was then UEFA's general secretary -- "directly negotiated an agreement with Manchester City", bypassing the Financial Control Panel of European football's governing body.
FIFA blasted the claims as an attempt to "undermine the leadership" of the global body.