West Ham co-chairmen David Sullivan and David Gold have complained of being targeted for abuse by Leicester supporters in Sunday's draw at the Walkers Stadium.
The 2-2 result came as a blow to Leicester's Barclays Premier League title ambitions, with only a late penalty from Leonardo Ulloa sparing the Foxes from defeat.
Leicester led through Jamie Vardy's goal, but the striker was later sent off and Andy Carroll's penalty drew the teams level before Aaron Cresswell fired West Ham ahead. Carroll's challenge on Jeff Schlupp was punished with the stoppage-time penalty from which Leicester forced the draw.
Sullivan told the Daily Mirror : "We didn't stay to applaud our own players off as we felt threatened. We've spoken to Leicester and they've told us they would look into it."
Gold wrote on Twitter: "Elderly Leicester fans turned into monsters when WHU went 2-1 up then returned to nice old people when LCFC equalised."
He added on Tuesday : " I want Leicester to win the PL and I am pleased for their fans but their behaviour towards us was unacceptable."