Police describe the behaviour of the cyclist as "completely incomprehensible," saying that he "filmed the dying man in an unconcerned way" instead of helping.
The motorcycle had attempted an illegal overtaking manoeuvre at around 3pm on Sunday near outside Ulm in Baden-Württemberg, police report.
As he cut back into the right lane of traffic he lost control of his vehicle, first smashing into a crash barrier and then hitting a street lamp. His injuries were so serious that he died at the scene of the accident.
The cyclist, who was at the scene as the accident happened, started filming the crash site and the dying biker on his mobile phone instead of calling the emergency services or attempting to provide him with first aid.
Even after medics arrived at the scene the man, aged between 20 and 25, kept on filming, impeding them in their work.
Police say that the cyclist was caught on camera, as a car at the scene had a camera on its dashboard. They are now investigating him for failing to provide help.
Several cases of road users knowingly impeding the work of emergency services on German streets have made headlines in recent months.
When a serious bus accident in July left 18 people dead, politicians accused drivers of putting people's lives at risk by slowing down to try and get a better view of the incident.
“It is indeed irresponsible and disgraceful when drivers in the opposite lane of traffic drastically reduce their speed to be able to see what has happened,” the Transport Minister Alexander Dobrindt said at the time.