Arsenal have been fined £34,000 by FIFA and warned about their conduct regarding player transfers, the UK Mirror reports.
This follows an investigation into the transfers of Chuba Akpom and Joel Campbell in 2018.
Akpom left for Greek club PAOK, while Costa Rica forward Campbell signed for Italian side Frosinone.
However, sell-on clauses inserted in their contracts were variable, meaning if either returned to clubs in the UK, Arsenal would receive a bigger fee.
For Akpom, Arsenal would receive 40 per cent of the transfer fee if he moved to a British club, but only 30 per cent if he went elsewhere.
Frosinone would pay Arsenal 30 per cent of any fee if Campbell was sold back to the UK, but only 25 per cent if he went anywhere else.
The discovery of the sell-on clauses led to an investigation since January, having not been initially declared.
The FIFA disciplinary committee found the Gunners to be violating rules for entering into contracts that thus enabled it to influence other clubs, and also for failing to declare data in its Transfer Matching System.