Pietersen, who scored his 20th century today, was warned when he was on 98 as Sri Lankan bowler Tillakaratne Dilshan stopped twice in his delivery stride as the England batsman opted to reverse-sweep before the delivery of the ball.
Pietersen's action was in violation of Law 42.9.
Sri Lanka Cricket media manager Brian Thomas quoted Srinath as saying that if any England batsman repeated any such action five runs would be added to the home team as penalty.