A man who killed himself, his wife and three children left a note saying he had obtained a fake COVID-19 certificate, prosecutors says.

Investigators say the 40-year old man may have been afraid that he could face repercussions after his wife's employer discovered the document was not authentic. 

Since late November, it has been compulsory for German workers to have documentation showing they have been vaccinated, recently recovered from COVID-19 or have a negative test result from the past two days.

The man, a woman and three children aged 4, 8, and 10 were found with bullet wounds in Koenigs Wusterhausen near Berlin on Saturday. Police are not looking for anyone else in connection with the crime.