A Swedish artist who drew an offensive Prophet Muhammad sketch died in a traffic accident.
Lars Vilks was reported to be travelling in a civilian police vehicle which collided with a truck near the town of Markaryd in southern Sweden.
Two police officers were also killed and the truck driver was injured.
The 75-year-old artist had been living under police protection after being subjected to death threats over the cartoon.
The cartoon, published in 2007, offended many Muslims who regard visual representation of the Prophet as blasphemous. It came a year after a Danish newspaper published cartoons of the Prophet.
Prime Minister Fredrik Reinfeldt had to meet ambassadors from 22 Muslim countries in an attempt to defuse the situation. Shortly afterwards, al-Qaeda in Iraq offered a $100,000 reward for his murder.
A statement from police said it was still unclear how the collision occurred, but initially there was nothing to suggest that anyone else was involved.
“This is being investigated like any other road accident. Because two policemen were involved, an investigation has been assigned to a special section of the prosecutor’s office,” a police spokesperson said.
Local media reported the police car in which Vilks was travelling in was at high speed. A large fire broke out after the accident and a number of emergency vehicles attended at the scene.