Kevin Crehan, 35, was arrested last year after leaving a bacon sandwich outside a Bristol mosque.
He was sentenced to one year in prison for the hateful act.
This week he was found dead in prison.
British authorities are not discussing the circumstances of his death.
Officials are investigating his death in prison.
A man serving 12-months behind bars for leaving a bacon sandwich outside a mosque has been found dead in his prison cell.
Kevin Crehan, 35, was jailed along with three others in July this year after the gang left rashers of bacon on door handles of the Jamia Mosque in Totterdown, Bristol.
Crehan, Alison Bennett, 46, and Mark Bennett, 48, and Angelina Swales, 31, admitted hurling racial abuse at a member of the mosque and leaving a St George’s flag tied to a fence nearby.
Images posted on Facebook showed bacon sandwiches left outside the place of worship.
A judge at Bristol Crown Court described the incident as “an attack on England”.
The prison service confirmed Crehan was found dead in his cell at HMP Bristol on Tuesday.
A spokesman told the Sun: “HMP Bristol prisoner Kevin Crehan died in custody on Tuesday 27 December.
“As with all deaths in custody, the independent Prisons and Probation Ombudsman will investigate.”