The public prosecutor’s office in Koblenz has opened an investigation into the district administrator of the Ahrweiler district on suspicion of negligent homicide and negligent.
The bodily injury caused by omission was due to the disastrous flooding in the area.
Friday’s probe focuses on Juergen Pfoehler, a Christian Democrat, CDU, politician and relates to his alleged failures on the evening of July 14, when he may have had sole decision-making powers.
The region was roiled by deadly flooding and suffered extensive destruction.
They said prosecutor was also investigating another member of the crisis team who took charge at least temporarily.
The death toll in the Ahr Valley currently stood at 141, with a further 17 people still missing.
Some 42,000 people were affected, with many seeing their homes and possessions devastated.
The prosecutors said there had been sufficient factual evidence that a warning should have been issued and possibly an evacuation ordered at around 8.30 p.m. on Wednesday July 14.
Negligence could have contributed to the number of deaths and injuries.
An evaluation of investigations into the deaths of flood victims showed that the fatalities occurred largely downstream of Ahrbrueck with many in the town of Bad Neuenahr-Ahrweiler, they said.
Mr Pfoehler immediately cancelled a news conference he had called on Friday to address the current situation.