BBC Sport says West Ham are trying to resolve an issue that has arisen around the £25m transfer of Benrahma from Brentford.
Benrahma had the first part of his medical on Thursday and the Hammers were confident of concluding a deal before today's 17:00 BST deadline.
However, it is understood a complication has arisen.
Sources say they still expect the transfer to go through.
Yet, amid claims the problem relates to his medical, the move is still to be completed, with club sources indicating they are trying to find a solution.
Need a VPN? Or seeking to switch? Then support Tribal Football by clicking here to sign up with our official partners NordVPN. Not only will you receive the best VPN experience, but also great discounts by signing up via Tribal Football. Thanks for your support!