Tyndall, who was due to appear at Leeds Crown Court on Thursday facing two counts of using words or behaviour intended or likely to stir up racial hatred, died at his flat in Westbourne Villas, Hove, East Sussex.
A Sussex Police spokeswoman said there were no suspicious circumstances surrounding Tyndall's death, which was reported by his wife at 8.15am today.
A coroner's investigation has been launched and an inquest will be held in due course, the police spokeswoman said. She said Tyndall was 72.
Tyndall was charged with BNP leader Nick Griffin, 45, following a long running investigation into the BBC documentary A Secret Agent, which secretly filmed BNP activists.Reuse content