Television replays showed South African fielder Faf du Plessis rubbing the ball on his trousers which had a zip on them, in an apparent attempt to tamper with the ball.

Umpires rod tucker of Australia and England's Ian Gould called South African captain Graeme Smith, changed the ball and added five runs to Pakistan's score.

Pakistan were struggling at 62 for three with Dale Steyn about to start the 31st over when the umpires took notice of the ball and took the decision.

Under ICC rule 42.1 on tampering, if an umpire spots a change in the condition of the ball but doesn't know who is the culprit, he will issue a first and final warning to the captain and the ball will be changed.

But in this case the umpires saw Du Plessis rubbing the ball in an apparent move to tamper with the ball and they called smith and docked five penalty runs.

An ICC spokesman confirmed the incident.