The Swedish artist Lars Vilks has died from a traffic accident on Sunday, Swedish police confirmed.

The artist had lived under police protection since his 2007 sketch of the Prophet Muhammad with a dog’s body brought death threats. 

The accident reportedly involved a truck colliding with a civilian police car in which Lars Vilks and his police protection were travelling, according to local news outlets.

Swedish police speaking to CBS News on Monday confirmed reports that Vilks, 75, was killed in the crash while in police protective custody.

Newspaper Dagens Nyheter said the artist’s partner had also confirmed his death.

The cause of the accident is under investigation.

Mr Vilks was largely unknown outside Sweden before his Muhammad drawing. At home, he was best known for building a sculpture made of driftwood in a nature reserve in southern Sweden without permission, triggering a lengthy legal battle.

He was fined, but the seaside sculpture – a jumble of wood nailed together chaotically – draws tens of thousands of visitors a year.

Mr Vilks’ life changed radically 13 years ago after he sketched the prophet with a dog’s body. Dogs are considered unclean by conservative Muslims, and Islamic law generally opposes any depiction of the prophet, even favourable, for fear it could lead to idolatry.

Al Qaeda put a bounty on Mr Vilks’ head, and in 2010 two men tried to burn down his house in southern Sweden.

Last year, a woman from Pennsylvania pleaded guilty in a plot to try to kill him.

Bjorn Wiman, the arts editor of the Dagens Nyheter paper, called Mr Vilks’ death a “complete shock.”

“Lars Vilks has, for over 10 years, lived with constant threats to his life, with bodyguards, like a prisoner in his own home, and has received death threats from one of the world’s most dangerous terrorist organisations. 

“And then he dies in a traffic accident on a motorway in Smaland. Unbelievable. 

“I think that Lars Vilks will go to history – and he would have anyway – but he will do it even more now as the early 2000s’ most important Swedish artist.

“Hopefully the Swedish cultural establishment will learn something from this – that when people are threatened it’s our task and duty to protect them,” Mr Wiman said.