Prosecutor Koos Plooy described Bouyeri as a "key figure" in an organization known as the Hofstad group, The Australian reported. Plooy was speaking at a procedural hearing on the group Tuesday in Rotterdam.
"Bouyeri took literature from the Internet which preached and glorified the use of violence. He himself wrote articles in which he advocated the use of deadly violence," Plooy said.
The Dutch court's procedural hearing involved 12 suspected members of the group, all young Muslims mostly of North African descent, who were arrested after the murder of van Gogh in an Amsterdam street.
The prosecution asked that the suspects be held in custody for another 90 days while the investigation continues.
Van Gogh's body was found with a note containing quotations from the Koran. The distant relative of 19th-century painter Vincent van Gogh was shot and stabbed while bicycling in Amsterdam last November. He had angered Muslims with his short film "Submission," depicting domestic violence toward Muslim women.