Police in Winsen, Lower Saxony, said 41-year-old father Marco was last seen at 7:30am on Thursday morning driving a gray Dacia Sandero.
But the car was back at the family home when acquaintances reported the family missing to police on Friday.
A police spokesperson for the larger district of Harburg told The Local that friends could not get in touch with the family and they had not said the were going away.
"At the moment, officials are still searching for where the family could be," the spokesperson said, adding that they do not currently have an explanation for the family’s disappearance.
One thing that was missing from the family’s house was a man’s green bicycle.
Police have been searching for the family using helicopters, search dogs and sweeping nearby woods as well as the banks of the Elbe River.
The spokesman said that police will be searching near the family’s "beloved swimming spot" on the Elbe on Tuesday.
Winsen police are asking that anyone with information contact them at 04171 / 7960.