Gohil died on Saturday, they said.
The National Investigation Agency had arrested him in the Best Bakery case in 2013.
In March 2002, a mob attacked the Best Bakery in Vadodara during the post-Godhra riots and burnt it down, killing 14 people.
After the Vadodara Court acquitted a few of the accused, the Supreme Court ordered a retrial in Mumbai. Four accused, including Ramesh and his father Jayanti, were declared absconding after they failed to appear before the court for the retrial.
Ramesh collapsed while taking a walk inside the prison and was rushed to J J Hospital where he was declared dead before admission, police said.
An inquiry would be conducted into his death, officials added. He was cremated in Vadodara.