Malcolm Sinclair was the brother of Jeffrey Sinclair. At one point, his brother gave him his only copy of the program "Frontiers of Laughter. A Twenty-four-Hour History of North American Comedy," featuring their mother, Gemma Gildea Sinclair. By 2259, Malcolm was living on Earth on the Australian continent and kept some of Jeffrey's things. When Jeffrey was assigned as an ambassador to Minbar, Malcolm was unable to send anything to him because all contact with his brother was blocked and they were only able to talk to each other once.