He shared the stage with Buffett and Bill and Melinda Gates speaking about his philanthropic activities that are focussed on educating the underprivileged.

FORBES: Bill Gates, Warren Buffett court India's richest

Since the launch of the Bill and Melinda Gates Foundation, Gates has become a leading figure on the international development stage, seeking innovative solutions to extreme poverty and poor health in developing countries.

BBC: Bill Gates to deliver Dimbleby lecture

The judgment follows from a two-week hearing last month in which Mr Gates, from High Wycombe, said that nine days after going to see Mr McKenna's stage show, during which he was invited up from the audience to take part, he suffered an acute schizophrenic episode and had to be admitted to hospital.

BBC: Hypnotist cleared