AFP - The car driver who had sought to ram the Dutch royal family but killed five onlookers died from his injuries on Friday, the prosecution service said.
"The 38-year-old man from Huissen (in the eastern Netherlands) who is suspected of an attack on the royal family, died of his injuries in hospital at 02:58 am (0058 GMT)," spokesman Wim de Bruin told AFP.
He had suffered severe brain trauma.
"His death means the end of the criminal investigation against him," said de Bruin, adding the investigation would continue in a bid to determine what had happened and whether more people were involved.
Officials said Thursday they had arrested the driver of the black car which slammed into the foot of a monument after mowing down people gathered for the annual Queen's Day royal procession in the central city of Apeldoorn.
The man, identified in the Dutch press as Karst S, had confessed to police that his action was aimed against the royal family, before being hospitalised with critical injuries.
Eleven people remained injured in hospital Friday.
"A search of the home of the suspect yielded no weapons, explosives or indications of a broader conspiracy," said a prosecution statement.
Dutch media reported Friday that the man had recently lost his job and appartment.