A manhunt is under way in Germany after three members of a family were found dead inside their home.

German police officers were seen on Monday using helicopters to scour the area surrounding Weitefeld, a village of 2,000 residents in the Rhineland.

The victims are a 47-year-old man, a 44-year-old woman and a 16-year-old boy, according to police, and are all members of the same family.

Their deaths are being treated as a suspected murder investigation, and police are seeking a man who was spotted fleeing the scene in the early hours of Sunday morning.

A police spokesman said there were indications the killer used knives and firearms to kill his victims.

Police also found cable ties inside the apartment, indicating the victims may have been tied up before they were killed.

Forensic investigators found bloodstains on a windowsill in the apartment, according to German tabloid Bild. Further traces of blood were also found on the street leading away from the scene of the crime.