Infosys shares nosedived nearly 14 per cent on Tuesday in their worst single-day drop in over six years, a day after India's second largest IT services company said it had received anonymous whistleblower complaints alleging certain unethical practices. While whistleblowers accused CEO Salil Parekh of leading an effort to shore up profits through irregular accounting, Infosys said one of the complaints dealt largely with allegations relating to his international travel to the US. The allegations come just two years after Infosys endured a shake-up that saw its top boss Vishal Sikka leave the company.