Born in Calcutta, Thomas was taken to South Africa when he was six years old. He moved to England in 1967, where he has written, directed and produced 40 major documentaries and dramas. He is also author of a highly-acclaimed biography Rhodes, the Race for Africa.

Thomas's films have taken the top prizes at numerous documentary festivals, including the most prestigious -- the US Emmy Award, the George Foster Peabody Award, the British Academy Award and the Grierson Award for best British Documentary. Two of his documentaries, Twins - The Divided Self and Man and Animal won fourteen international awards between them.

Thomas has succeeded in creating programmes with a strong message that are also highly popular. The opening programme of his 1998 series on obesity, Fat, won three awards from the British Medical Association and was also one of the ten most popular programmes of the week in the UK, with an audience of 9.5 million. When his drama Death of a Princess was originally shown in the United States, it earned one of the highest ratings in the history of PBS, while his 2004 programmes on the Ancient Greek Olympics were sold to 83 countries.

In 2007, his documentary,The Tank Man, was invited for special screenings at the US AGM of Amnesty International and the United States Congress.

His latest offering, a two-hour documentary on The Qur’an, was first shown on British television (Channel 4) on July 14th 2008 and on American television (National Geographic) on August 5th 2008.