Rooney blasts booing England fans
The Football Association has made a complaint to World Cup organisers Fifa after a fan breached security and entered the England dressing room.
The incident came after England's 0-0 draw with Algeria in Group C at the Cape Town Stadium.
The intruder was escorted out shortly after a "few verbals" but the incident has angered the security-conscious FA.
"This is not acceptable and thankfully no serious harm was done," read an FA statement on Friday evening.
Princes William and Harry, who have been on a tour of southern Africa, were in attendance in Cape Town and had been present in the dressing room after the match.
However, both members of the Royal family had left the dressing room by the time of the security breach.
FA spokesman on security lapse
"There is a lot of Fifa security in the stadium but unfortunately one fan got through all of that and managed to get into the dressing room after the game but thankfully no real harm other than a few verbals," said Adrian Bevington, managing director of Club England.
The FA will expect security to be watertight as England head to Port Elizabeth for their final Group C match against Slovenia on Wednesday 23 June.
"Thankfully no real damage done but we got to make sure this can't happen again for us or for any other team," added Bevington.
Purshoth Chetty, managing director of the Cape Town Stadium, insisted a full investigation would take place into the why the fan had "slipped through the crack" in security.
Chetty said: "This merits a serious review. Our security process covers all aspects and we do not believe we will need to change our general arrangements. But we are conducting a full analysis of how this happened.
"It's not our security people's fault, they do a sterling job wherever they go. I'm sure Fifa will accept responsibility for this and we have to make sure it doesn't happen again."
Fifa spokesman Nicolas Maingot said the governing body was not prepared to lay blame until the matter was further investigated.
Fifa - security will be tightened
"It is of course totally unacceptable for Fifa that a fan finds his way up into a dressing room of any participating team at any Fifa competition," he stated.
"This has been discussed at the daily security meeting of the local organisers, police and Fifa. Security will be tight to ensure it will never happen again."
England's travelling fans showed their displeasure with their team's efforts by booing them off the pitch at the end of their second group game.
Striker Wayne Rooney looked into a TV camera and said: "Nice to see your own fans booing you, that's what loyal support is".