He reached this conclusion after investigating to find evidence that either woman (Margaret Howard and Jane Conway) had ever existed, talking to people who had known Burt for many years.
[5][6] He has also researched the adverse health effects of vitamin D deficiency, specifically, that caused by insufficient exposure to sunlight.
His father, John Gillie, was a nautical instrument maker and his mother, Ann (née Philipson), studied fine art in Newcastle and Paris.
In 1969, he married his second wife Louise Panton, a documentary film-maker, and they had two daughters, Lucy and Juliet, but divorced in 1991.
In 1999, he married Jan Thompson, a journalist and managing editor of The Guardian, and they had two sons, Calder and Sholto.