Pioneering American comedian Dick Gregory has died. He was 84.

As well as being a major stand-up star appearing frequently on American television Gregory became vocal as a civil rights campaigner. In 1968 he stood for election as US President on behalf of the Freedom and Peace Party and received 47,097 votes. He regularly spoke about racism and segregation in his act: "Segregation is not all bad. Have you ever heard of a collision where the people in the back of the bus got hurt?"