NIJMEGEN - Two half-brothers of murdered boxing champion Kevin America have started their own search for the killer. The two have run out of patience with the police.

Police arrested the two men last week for allegedly threatening people in their investigation. For example, the two visited persons in Nijmegen who they believe should know more about the murder of their 36-year-old half-brother.

The men, 32 and 42, spent three days in pretrial detention, according to their lawyer Francoise Landerloo. They have since been released.

Landerloo states that the half-brothers are very dissatisfied with the police investigation, she says in De Gelderlander. "But they have not threatened anyone. The magistrate judge also released them."

Kevin America was shot dead in his hometown of Nijmegen in January. In recent months, several people were questioned, but so far the perpetrator has not been apprehended. However, several witnesses and people have been heard, including four people who were arrested in January.