A 25-year-old man was killed in custody by the Wuppertal police.
He died last Monday, announced the Wuppertal public prosecutor and the police in Hagen on Sunday.
For reasons of neutrality, the police in Hagen took over the investigation.
A taxi driver had alerted a police patrol at night, the authorities said.
The 25-year-old had a violent argument with his sister, with the 34-year-old injured.
The dispute has shifted from the taxi to the street.
According to the autopsy, there was no evidence of third-party negligence
When the police wanted to take the incident on record, the 25-year-old attacked a policewoman and knocked her to the ground.
The police officer standing next to him then tried to overpower and tie up the attacker.
The man resisted massively.
Only with reinforcements was it possible to tie up the unruly 25-year-old and bring him into police custody.
Two police officers were slightly injured.
Because there was suspicion that the 25-year-old was under the influence of alcohol and other drugs, a blood sample was taken from him by a doctor. The 25-year-old suddenly lost consciousness. The doctor and later an emergency doctor who was called in had tried in vain to reanimate the young man. The autopsy has since shown that the man died of an underlying disease in conjunction with his drug use. Indications of third-party negligence or violence as the cause of death were not discovered.
The police headquarters in Hagen is conducting a death investigation, which, according to the information, is not directed against the police officers deployed.
The public prosecutor's office in Wuppertal is also investigating an unknown person who is said to have left the drugs to the 25-year-old.
They did not disclose why they did not report the incident until less than a week later.
Several media had previously reported.