"Waller underwent a re-assessment of his bowling action, following remedial work at the University of Pretoria earlier this month, with such assessment concluding that the amount of elbow extension in Waller's off-spin deliveries was within the 15-degree level of tolerance permitted under the ICC Regulations," said the ICC in a statement.
It added: "The umpires are still at liberty to report Waller in the future if they believe he is displaying a suspect action or that he is not reproducing the action that has been declared legal during this assessment. To assist the umpires in this respect, they have been provided with images and video footage of the bowler's legal bowling action."