Melinda Vinalis, a work colleague of British football coach Mike Jones, told ITV1's Daybreak: "I couldn't imagine his last moments, that was hard for me. How much he suffered and that he was alone."
More top news
Rain will linger across the south for much of today, slowly clearing away through tonight
The Equality and Human Rights Commission report said the deaths are attributed to a "failure" in the care of police suspects and prisoners.
Labour leader Jeremy Corbyn was disrupted from delivering a speech by a protest led by human rights campaigner Peter Tatchell.