The Daily Mail has pictures which it says show Akhtar running his left thumb along the ball's seam before dropping the ball on the ground and standing on it with his spiked right boot.
The pictures were taken in the 41st over of England's innings in Southampton as Shoaib prepared to bowl to Paul Collingwood [ Images ].
England won the match by 121 runs to take the series.
Four years ago, Sky News cameras filmed Akhtar flicking at the ball with his thumb during a one-day international here against England.
On that occasion Shoaib was cleared but was warned about his behaviour after being accused of tampering with the ball during a Test match in Zimbabwe in late 2002.