JOHANNESBURG -- FIFA says it's unacceptable that an angry fan broke through security lines and entered the England players' locker room in Cape Town after the 0-0 draw Friday with Algeria.
FIFA spokesman Nicolas Maingot says security will be tightened to ensure such an incident never happens again.
Organizing committee spokesman Jermaine Craig says there was no physical threat to the team, and local police are investigating.
England officials complained to FIFA about the security lapse, which happened after Prince William and Prince Harry had visited the team in the locker room.
Prince William joked about the incident afterward, saying the breach happened because they had "left the door open."
"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," Adrian Bevington, managing director of Club England, said.
The man is reported to have verbally confronted players and had an angry exchange with English star and former team captain David Beckham before being escorted from the stadium.
Beckham said later, however, that the fan casually walked in, said something derogatory to him and walked out again. There was no scuffle or aggression, he said.
Police spokesman Colonel Billy Jones said the man, who was wearing a red T-shirt, was wanted for trespassing, according to The Telegraph newspaper. There was no reason given for why the man was not handed over to police, instead of being allowed to leave the stadium.
The security breach was just one of many problems the England team is facing.
British media condemned the team as a shambles and criticized a sullen Wayne Rooney for his reaction to fans who jeered the players off the field Friday night.
Rooney shouted at a television camera: "Nice to see your own fans booing you. If that's what loyal support is ... for [expletive] sake."
The striker issued an apology Saturday afternoon.
"I am as passionate about the England team as anyone," Rooney said in a statement. "Last night, on reflection I said things in the heat of the moment that came out of frustration of both our performance and the result.
"For my part I apologize for any offense caused by my actions at the end of the game."
That was after The Daily Mail ran a picture of Rooney under the headline "Raging Fool" and The Sun's front page blared: "Roo blows fuse over boos."
The Daily Mirror offers that England coach Fabio Capello has put too much pressure on the forward.
"From the moment the Italian came into the job, his entire approach has been about one idea, geared towards Rooney," it said. "He changed the shape of the team to make him the central figure, told the planet to beware and made the Manchester United man his talisman.
"But last night England did not have Wayne Rooney. Yes, they had a fellow called Rooney playing in the No. 10 shirt, but they did not have Wayne Rooney."
England is tied with the United States with two points in Group C. Algeria has one, and Slovenia -- England's next opponent -- leads with four. Failure to advance to the second round would be among the biggest soccer debacles in England's sports history, especially after the impressive qualifying campaign that raised hopes of a first major title since winning the World Cup on home soil in 1966.
Information from The Associated Press was used in this report.