According to the Robert Koch Institute (RKI), the reproduction rate - the estimated number of people a confirmed patient infects - is now above 1.
This means the number of infections is now rising in the country.
The report came as thousands of Germans gathered on Saturday calling for a total end to the lockdown.
Chancellor Angela Merkel announced a broad relaxation of national restrictions on Wednesday after talks with the leaders of Germany's 16 states.
All shops are allowed to reopen, pupils will gradually return to class and the Bundesliga - Germany's top football league - will restart as soon as next weekend.
But there were protests across the country on Saturday, as some called for measures to be lifted even faster.
Germany has the seventh-highest number of confirmed cases in the world, with latest RKI data on Sunday showing the reported infected tally at 169,218 and a reported death toll of 7,395.