Crystal Palace loaned Alexander Sortloh to Trabzonspor on a two-year deal last summer with a buy option.
But there has been confusion over the terms of the deal.
NTV Spor have revealed details of the agreement.
Trabzonspor have an obligation to buy Sorloth for €6m which will be activated if the Norway international starts in 50 percent of his sides games over the 2020-21 season.
The Black Sea based outfit reportedly paid Palace €750,000 as a loan fee for the two-year deal.
Palace are unable to recall Sorloth as part of the deal.
Sorloth has already scored 31 goals and provided 10 assists in all competitions for Trabzonspor this season.
Palace in contrast have scored just 30 goals in the Premier League this season.
The Norway international is the top scorer in the Super Lig with 23 goals and still has two games left to increase his tally.
Trabzonspor will finish the season as runners-up and have the chance to win the Turkish Cup.
The Black Sea Storm will face Alanyaspor on 29 July in the Turkish Cup final.