England duo Stuart Broad and Steven Finn were reportedly in attendance during the alleged physical attack made by Australia batsman David Warner on Joe Root.
The 26-year-old is being investigated by Cricket Australia over the accusations of the incident, which is said to have taken place in a Birmingham bar following England's win over the Aussies on Saturday.
Chris Barrett, who writes for the Sydney Morning Herald, told BBC Radio Five Live that Root was punched once by Warner while Finn and Broad were also at the venue.
Reports have claimed that Warner could be sent home from the ICC Champions Trophy tournament.