Leicester did not want to sell Islam Slimani to West Ham because the former Premier League champions are still annoyed over comments made by Karren Brady previously.
The Hammers vice-chair wrote about Foxes chief Vichai Srivaddhanaprabha and his sacking of Claudio Ranieri in a weekly newspaper column last year.
West Ham manager David Moyes missed out on the signing of Slimani on deadline day as the 29-year-old striker was sent to Newcastle instead on loan.
Multiple sources have said West Ham officials apologised to Leicester but that it is not water under the bridge as far as the King Power club are concerned.