SHANGHAI/LONDON, July 9: – GlaxoSmithKline said yesterday it was investigating new allegations that its staff had used improper tactics to market Botox in China, but had so far found no evidence of bribery or corruption. The move follows a claim that GSK staff allegedly handed doctors cash and other rewards for prescribing Botox treatment, which the British group sells in China under an agreement with patent-holder Allergan. (agencies)