Johannesburg - England star Ben Stokes apologised on Friday for his angry exchange with a fan during the fourth and final Test against South Africa but claimed he was the victim of "repeated abuse".

Stokes described his reaction at the Wanderers as "unprofessional".

English cricket chiefs, however, claimed staff and players were subjected to "personal abuse during and after the day's play".

Stokes, the outstanding player in a series which England lead 2-1, stopped briefly as he left the field after being dismissed for just two and appeared to challenge a spectator, who evidently insulted him.

"Come say that to me outside the ground, you fucking four-eyed cunt," Stokes said, according to television footage captured as he left the field and started to climb the steps leading to the dressing room.

Witnesses told the Guardian newspaper that a middle-aged man, wearing a South Africa one-day cricket team shirt, had targeted Stokes, allegedly calling him a "ginger cunt" and likening him to pop star Ed Sheeran.

"I wish to apologise for my language that was heard on the live broadcast today after my dismissal. I should not have reacted in that way," Stokes said in a statement released on his Twitter account.

"As I was leaving the playing area, I was subjected to repeated abuse from the crowd. I admit that my reaction was unprofessional, and I sincerely apologise for the language I used, especially to the many young fans watching the live telecast around the world.

"Throughout the Tests so far, the support from both sets of fans (England and South Africa) has been brilliant. One incident will not ruin such a competitive series, which we are determined to win."

England all-rounder Stokes could face disciplinary action for uttering an audible obscenity, which is a level one offence according to the International Cricket Council's code of conduct.

Ashley Giles, managing director of England men's cricket, asked for security and stewarding to be improved for the remainder of the match.

Giles said it was "disappointing" that a member of the public had abused Stokes but said, "Ben is fully aware that he should not have reacted in the way he did."

Giles said members of the England support staff had also been subjected to personal abuse during and after the day's play.

"We have requested to the venue to ensure that security and stewarding are enhanced for the remainder of the match so that players and staff members can go about their duties without provocation," he said.

England were 192-4 at the end of the rain-shortened first day.

Spectators at the Wanderers have a reputation for being among the rowdiest in the world, going back to 1994/95 when Australians Merv Hughes and Shane Warne were both subjected to abuse from the crowd.

Hughes lashed out with his bat, hitting a wire fence, which was all that separated players from spectators, after being abused as he walked up a long series of steps leading to the dressing rooms after being dismissed in a Test match.

Following that incident a plexiglass cover was erected over the steps, separating players from spectators in what was jocularly renamed the 'Merv Hughes tunnel'.

The incident involving Stokes happened just before the player stepped into the protected environment of the tunnel.