French giants Marseille ratified their annual accounts on Friday, revealing a loss of some 15 million euros ($20.8m) for the last financial year.
The club's board confirmed the loss at a meeting in Paris.
The news comes after Marseille owner Margarita Louis-Dreyfus told the daily newspaper Le Monde on October 8 that she had injected a sum of 20 million euros ($27.75m) into the club over the summer.
In the same interview, Louis-Dreyfus issued a veiled threat that she could sell the club if on-field performances did not improve soon.
Didier Deschamps's side have won two out of two in the Champions League group stage ahead of their meeting with Arsenal next midweek, but have won only once so far in their domestic league, and lay 13th in the table ahead of the weekend's matches.