Olympique Lyonnais were left unhappy with West Ham United on Friday and accused the latter of showing a "profound lack of respect" after Algerian forward Said Benrahma's proposed transfer to the French club didn’t go through.
Lyon said the English club did not meet the requirements on world football governing body FIFA's transfer matching system for the deal to go through on Thursday before the January transfer window ended.
"Following this incomprehensible behaviour... the international transfer certificate could not be requested before closing time," Lyon said in a statement.
"Olympique Lyonnais deeply regrets this situation and this decision, demonstrating a profound lack of respect on the part of West Ham towards the institution and the player," it said.
"The club reserves the right to initiate all appropriate procedures necessary to validate the transaction at a later date, and to hold West Ham responsible if necessary."
West Ham did not respond to Lyon's comments about why the transfer collapsed, but confirmed in an email to Reuters that the deal was not completed in time.
