Ligue 1 side Lille are reportedly still owed around £10m from Arsenal for the sale of Nicolas Pepe in 2019.
The Gunners smashed their all-time transfer record to bring in the Ivory Coast international four years ago, agreeing to fork out a whopping £72m for his services.
Arsenal's extortionate fee blew the hitherto stiff competition out of the water, as Pepe agreed a five-year deal with the Gunners, who were under the wing of Unai Emery at the time.
The 28-year-old moved to England on the back of a 22-goal and 11-assist season in Ligue 1 during the 2018-19 campaign, but he failed to recapture the form he showcased in the French top flight.
Pepe's underwhelming four-year spell in North London came to an end last week, as Arsenal agreed to terminate his contract and allow him to join Turkish outfit Trabzonspor on a free transfer.
The Gunners were originally hoping to recoup a small fee for the attacker, who was dethroned as Arsenal's all-time record signing this summer by Declan Rice, but no suitable offers were forthcoming.
Rather than continue to pay his reported weekly wages of £150,000 for the final year of his contract, Arsenal ripped up Pepe's deal and accepted a major loss on their £72m investment.
However, the Evening Standard claims that the Gunners still have an outstanding payment of around £10m left to settle, having spread the cost of his transfer over his five-year contract.
Arsenal are only believed to have paid half of Pepe's wages while he spent the 2022-23 season on loan with French side Nice, where the Ivorian also agreed to lower his salary by around a quarter.
Pepe managed a respectable eight goals in 28 games at the Allianz Riviera, but he also struggled with injuries and was informed that he had no future at Arsenal by Mikel Arteta following his return.
While in North London, Pepe found the back of the net 27 times and provided 21 assists in 112 games for Arsenal, winning one FA Cup during his first campaign at the Emirates.
A moderately successful 2020-21 campaign at individual level saw Pepe net 16 goals in all tournaments, including 10 in the Premier League, seeing him finish second in the voting for the club's Player of the Year behind Bukayo Saka.
However, Pepe managed just one goal in the 2021-22 Premier League season against Wolverhampton Wanderers and would have found himself behind Reiss Nelson and Fabio Vieira in the pecking order this season.
The Gunners have sought to move away from high-profile contract terminations in recent months, but Pepe still joins a lengthy list of renowned names to leave Arsenal in such a way, including Mesut Ozil, Pierre-Emerick Aubameyang, Hector Bellerin, Willian, Henrikh Mkhitaryan and Sokratis.
The 28-year-old is the only senior Arsenal player to have his deal ripped up this summer, though, as fees were obtained for all of Folarin Balogun, Granit Xhaka, Matt Turner, Auston Trusty, Rob Holding and Pablo Mari, while Ainsley Maitland-Niles left on a free transfer upon the expiration of his contract.