Cape Town - Proteas off-spinner Johan Botha has been signed by the reigning IPL champion Rajasthan Royals after being cleared by the ICC.Botha was recently cited for his bowling action, but tests in Australia found that, with one exception, there is no problem.The exception is Botha’s doosra, the delivery that turns away from the right-hand batsmen. He has been banned from bowling this delivery.Shane Warne, captain-coach of the Royals said, "Johan Botha is a sensational player and we were disappointed when he couldn't be part of our squad at the start of the tournament. It is a real boost that he can now make an impact when called upon. "Botha has become a key performer for South Africa in the middle overs of 50-over ODI matches with his ability to stop opposition sides from scoring. He is effective in Twenty20 cricket, too, with his batting and fielding skills making him a quality performer.