Police found the dead victims from gunshot wounds in a family home in Koenigs Wusterhausen south of Berlin on Saturday.
A man has taken his own life after killing his wife and their three young daughters.
The tragedy happened in Germany.
According to Dailymail, the man faked a Covid-19 jab certificate and feared his children would be taken away when it was discovered.
Police found two adults, both 40, and three children aged four, eight and 10 dead from gunshot wounds in a family home in Koenigs Wusterhausen south of Berlin on Saturday.
In a pages-long farewell note found by police, the man, named as Devid R, said he forged a vaccination certificate for his wife Linda.
Her employer had found out, prompting the couple to fear they would be arrested and lose their children Leni, Janni and Rubi, prosecutor Gernot Bantleon told news agency dpa.
Police were called to the house after being alerted by witnesses who had seen lifeless bodies in the house, police and prosecutors said on Saturday.
Investigators suspect that the man killed his wife and children and then himself. They found a gun in the house, but it wasn't immediately clear whether it was the weapon used to fire the fatal shots.
They found no indication that anyone else was present at the time or that anyone forced their way into the house.
Police said autopsies on the five bodies were underway and will determine how long the family had been dead.
The grisly case comes as Germany has been tightening up restrictions to try to stem a fourth wave of the coronavirus pandemic.
From last month, employees have been required to show they are vaccinated, recovered or test negative for Covid-19.
German authorities agreed last week to bar the unvaccinated from access to all but the most essential businesses such as grocery stores, pharmacies and bakeries, and they also plan to make vaccination mandatory for some jobs.