The match referee of Friday's World Cup quarterfinal between New Zealand and South Africa is investigating an altercation between the teams during the Black Caps' upset win.
New Zealand's 12th man Kyle Mills appeared to say something to South African batsman Faf du Plessis when he came onto the pitch shortly after AB de Villiers had been run out.
That led to a confrontation between the two sets of players, and an ICC spokesman said match referee Roshan Mohanama is "looking into an incident involving Daniel Vettori, Kyle Mills and Faf du Plessis."
There will be no further information until Saturday.
New Zealand won the match by 49 runs after South Africa had appeared to be heading for victory.